# Imagine: Yugang CO2 dream machine



## Yugang (11 Feb 2022)

As a hobbyist I would welcome new solutions for more reliable CO2 management, affordable and easy to operate.

Now just imagine….

I’ll share my thoughts on what would be my dream YUGANG (aquarium) CO2 machine – hopefully inspiration for innovative vendors who bring progress to the hobby.

Can’t avoid being technical - please skip and proceed to next topic, or continue at own risk.

                                                                                                                                                                               -------

As a hobbyist I really don’t care about regulators and CO2 bubbles, I care about having a system that stabilises CO2 in my tank. Some challenges with the components I have tried over the past years while learning and optimizing my approach to CO2:

Regulator. I don’t have skills of a swiss watch maker to tune it, and don’t like spending significant cash on a product with unpredictable performance.
In-tank diffusor. Only partially dissolving CO2 in the water, and loss of bubbles from water surface. Unless very well maintained, performance deteriorates over time.
In-line diffusor. Slightly better than in-tank, but often fragile with flooding risk and/or mist
pH/CO2 controller. Can be used to stabilise pH through timed CO2 injection, mitigating suboptimal regulator function. I don’t like sending alternating waves of high CO2 enriched water and not-enriched water into the tank, concerned about BBA. After several years, no longer using mine
CO2 reactor. Modified commercial product and some DIY, great and maintenance free
                                                                                                                                                                                  -------

So let’s for now forget using an expensive (500 USD and up) industrial grade regulator, and let’s imagine how a dream CO2 integrated system might look. *The function of this system would be to blow a flow of water enriched with a targeted ppm CO2 (stabilised, not alternating) into the tank:*

CO2 reactor, maintenance free
pH/CO2 controller, mitigating the instabilities inherent to the regulator, and enabling CO2 flow control
pH probe, mounted in the exit of the reactor (not in the tank)
Affordable CO2 regulator, no need for super precision, with stepper motor on needle valve axis, driven by pH/CO2 controller
Optional second pH probe, in tank
Optional circulation pump and spray bar
This system stabilises the outgoing water from the CO2 reactor at a target level (say 30 ppm) as measured by the pH probe on reactor exit.
Initially, after degassing during the night, the aquarium water pumped into the reactor will have a low CO2 ppm, therefore the controller will gradually increase CO2 injection so as to bring the outgoing water to the targeted ppm - say 30 ppm
As the incoming aquarium water CO2 ppm gets closer to the target, the CO2 regulator will gradually be dialled down by the controller / stepper motor, while still meeting the CO2 ppm target on the reactor exit.
The system is thus designed to ramp up fast before lights on, high injection, then maintain a stable CO2 ppm during the day with lower and continuously variable CO2 injection.

An integrated system, the user does not longer care for individual components, or bubbles.
Calibration is done while running in aquarium water, using a drop checker to set the target pH, and then ‘never’ look at it again.
When using optional in tank pH probe, the controller can be used for an even faster ramp up before lights on, turbo ppm from the reactor, without the risk for an overshoot over the target in the tank (shrimp/fish safety). After ramp up, the first probe at reactor exit resumes full control for the steady state during the photo period.
Optional circulation pump can be used to operate independent of filter.
Spray bar used to direct the CO2 enriched flow towards the bottom and back over the bottom and plants (for increased efficiency) with the main water flow

From a cost perspective this system would be slightly more expensive than reactor + hobby grade regulator + pH/CO2 controller (but less expensive than using an industrial or lab grade regulator), but it offers important additional benefits:

A very simple procedure for user to manage a reliable CO2 injection, with a user friendly system concept
User no longer concerned with regulator or counting bubbles. Instabilities of regulator are mitigated by feedback from pH probe and control system
A stable, not alternating, flow of CO2 enriched water
Fast ramp up before lights on, inherent to the systems control concept
If we take the idea one step further, we may dream of this system being integrated with a canister filter (minimize water pipes and loss of flow, ease of maintenance, minimize noise, reduced water leak risk), with the CO2 cylinder mounted to the canister as well.

I volunteer as a beta test site for any vendor developing this!

Cheers,
YUGANG (fishtank)
a.k.a. CJR


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## ian_m (11 Feb 2022)

Many people have been there thought that....but in the end failed...

This is compared to the simple equipment of a well adjusted quality regulator, needle valve, suitable injection system and drop checker. If setup right, bubble count, surface ripples the CO2 levels do this, see the green line (for instance) it levels out at 30ppm. Fantastic no computers required, no daily fiddling, job done.






The many issues with your idea(s) are:

Much too complicated compared to the above simple regulator and needle valve.
Much too expensive compared to quality regulator.
Too much complicated equipment to fail and gas your fish.
CO2 (pH) probes are not maintenance free, requiring frequent cleaning and calibration. At least weekly. How to you regularly remove a pH probe, for cleaning & calibration, from your equipment with all the water escaping ? More valves ? Suddenly becomes quite complicated.
Quality pH probes, suitable for continuous use and abuse in an aquarium cost £100's.
pH change is relative not absolute. You need to inject CO2 until pH drops by 1 compared to when injection started. This is why you use a drop checker as it measure CO2 levels in the water not pH of the water.
The assumed pH drop, that everyone reads from the "pH drop table" is for carbonate water . A fish tanks is not just carbonate water, contains a lot else, but luckily a 1pH drop generally under reads the CO2 level, which is why pH controlled CO2 doesn't generally gas all your fish.
High maintenance. It is a pain enough to regularly cleaning diffuser and piping. If you don't touch you needle valve during cleaning, all goes back to as it was. Cleaning such a high tech system will not be simple and probably require recalibration.
Software is now involved. I think you will find the software & testing will be horrendous in terms of time and cost.
I think the take up of such a device will be extremely low due to extortionate cost, over complicated equipment, poor reliability, high maintenance and in the end never able to work as you think it should.

The above is possibly why everyone (100% ?) use a simple regulator, needle valve and injector. Once setup it just works.

See here for my take on the maths behind simple CO2 injection.
CO2 concentration versus time. The maths...


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## arcturus (11 Feb 2022)

Very interesting ideas! A fundamental problem we would need to address is how to actually measure the dissolved CO2 concentration. If we rely on the pH probes, we will be dependent on what the water's pH will tell us. But the relevance of the pH readings is fully dependent on the buffering capability of the water: with low dKH, the value of pH is meaningless. So, we would be assuming a stable dKH level. But we know that we cannot safely make this assumption. For example, a simple water change can change these values, regardless of the type of water (RO, rain, tap water). This can wreak havoc with the pH readings and lead to the controller injecting lethal amounts of CO2.

Using good CO2 valves allows for stable CO2. Much simpler. I would rather prefer that vendors start shipping quality valves with their equipment.


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## Yugang (11 Feb 2022)

Of course I expect some push back, as I am rocking the boat and establishment.

So a quality CO2 regulator will be in excess of 500 USD. And now what?

I bring this idea out, believe that some out there understand and take it up. Future will tell.

PS enjoying quality time for HK friday night, will study the replies tomorrow.


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## Yugang (11 Feb 2022)

ian_m said:


> The many issues with your idea(s) are


I believe you just did not read my detailed explanation - nearly all your arguments, if not all are addressed.

A quality regulator costs in excess of 500 USD, we had lots of debate on that
A pH/CO2 controller costs 140 GBP, including probe

I would appreciate if you could study my posting carefully, and specify much more clearly where the key issue is.

PS. I have no ambition to develop a business in this area, that is why I posted in public domain. I have also no need to be right, or win any debate, I just want to serve the hobby by posting this in public domain.


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## arcturus (11 Feb 2022)

Yugang said:


> Of course I expect some push back, as I am rocking the boat and establishment.
> So a quality CO2 regulator will be in excess of 500 USD. And now what?



The issue is not the regulator. I would say that most (double-chamber) regulators that are available in the hobby are good enough for the purpose. The regulators are not high-precision devices. The expensive industrial regulators are designed to handle high pressures and/or high gas flows. This is not needed. The issue is the needle valve, which is the high-precision device. But I think a combo with decent double-chamber regulator and a good needle valve could be less than 500 USD. I am saying this based on a list of needle valves that was shared before.



Yugang said:


> A pH/CO2 controller costs 140 GBP, including probe


You wouldn't need a controller. Just a good needle valve. The pH probe is only needed to profile the CO2, not to control it.


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## Yugang (11 Feb 2022)

arcturus said:


> The pH probe is only needed to profile the CO2, not to control it


So you don't understand the technical concept of my posting. An affordable regulator/needle valve, yet controlled and corrected by the controller and probe.



arcturus said:


> Just a good needle valve


Yes, but as we discussed need to pay some 500 USD for that.

My aim is that some company, US, EU or possibly Asia will run with it. If I am wrong, nothing lost as I just tried to serve the hobby


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## Andy Taylor (11 Feb 2022)

I prefer to get my hands dirty instead of relying on hi tech gadgets. Too many things can go wrong with the lazy mans way.


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## Yugang (11 Feb 2022)

Andy Taylor said:


> I prefer to get my hands dirty instead of relying on hi tech gadgets. Too many things can go wrong with the lazy mans way.


I used to have a low tech tank, loved it


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## Nick potts (11 Feb 2022)

Yugang said:


> I believe you just did not read my detailed explanation - nearly all your arguments, if not all are addressed.
> 
> A quality regulator costs in excess of 500 USD, we had lots of debate on that
> A pH/CO2 controller costs 140 GBP, including probe
> ...



99% of CO2 users are not using regulators at that price point, many use things like the CO2Art  or similar options @$270 or even cheaper ones. While CO2 injection is a big issue at first, most eventually dial it in fine with whatever system they are using.

I don't use expensive equipment for my CO2, I probably paid less than $100 all in and while it took me a while to get my head around injecting in general, my kit has never given me any issues.


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## bazz (11 Feb 2022)

ECINU
		

Has this not already been posted?


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## erwin123 (11 Feb 2022)

While there may be some may need such a device it really isn't needed for 100 litre and smaller tanks. Its totally possible to get a stable CO2 level with inexpensive CO2 regulators for small tanks. Here's the pH profile of my tank (60x45x45) for reference with 0.03 variance. And my CO2 regulator is an ANS brand regulator, maybe half the price of a CO2 Art regulator


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## Yugang (11 Feb 2022)

Nick potts said:


> 99% of CO2 users are not using regulators at that price point, many use things like the CO2Art  or similar options @$270 or even cheaper ones. While CO2 injection is a big issue at first, most eventually dial it in fine with whatever system they are using.
> 
> I don't use expensive equipment for my CO2, I probably paid less than $100 all in and while it took me a while to get my head around injecting in general, my kit has never given me any issues.


So what regulator is recommended that is  living up to the expectations and stays stable for a couple of years?
I am on my third CO2 regulator, researched a lot for a real good one and gave up. Happy to admit if I am wrong, and go to the vendor that sells me for 100$ as you say (even 270 USD).

Specialists on this forum say that hobby grade are not up to standard, need to spend for the industrial or lab grade. 500-1000 USD.

Apologize again... rocking the boat


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## Nick potts (11 Feb 2022)

Yugang said:


> So what regulator is recommended that is  living up to the expectations and stays stable for a couple of years?
> I am on my third CO2 regulator, researched a lot for a real good one and gave up. Happy to admit if I am wrong, and go to the vendor that sells me for 100$ as you say (even 270 USD).
> 
> Specialists on this forum say that hobby grade are not up to standard, need to spend for the industrial or lab grade. 500-100 USD.
> ...



The boat is fine 

I am only giving you my experience with my own reg, of course you may have had different than me.

Have you looked at CO2 art, GLA etc?



Yugang said:


> Specialists on this forum say that hobby grade are not up to standard, need to spend for the industrial or lab grade. 500-100 USD.



They are a small minority, most will tell you a decent dual-stage hobby reg will work fine.


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## Yugang (11 Feb 2022)

erwin123 said:


> While there may be some may need such a device it really isn't needed for 100 litre and smaller tanks


Agree. I definitely am not saying that Yugang Co2 dream machine  is the solution for us all.

My tank, 200l is very well balanced and I continue to win the fight with my regulator. Yet, we also need to move the hobby forward. Some of us will be first movers, and time will tell how it evolves. I, and many on this forum have some level of dissatisfaction with their CO2 setup, and only with innovation we will move to the next level.

My message was first an foremost targeted at commercial vendors, as a challenge to innovate. I see a lot of pushback, judge for yourself if that serves us as hobbyists.


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## Yugang (11 Feb 2022)

bazz said:


> Has this not already been posted?


No, different concept and less powerful.


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## foxfish (11 Feb 2022)

I am on your side mate, a plug and go system with various alarms, easy to set up auto function and easy read digital  displays showing how much gas you have left, what the PH is and what the C02 content is.
At the moment we dont even have a really good off the shelf reactor available!


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## Yugang (11 Feb 2022)

Hanuman said:


> Virtually 100% of all regulators sold for aquariums are mediocre at best





Nick potts said:


> The boat is fine



Yeah 😠


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## Nick potts (11 Feb 2022)

Yugang said:


> Yeah 😠



As i said, a very small minority.


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## Yugang (11 Feb 2022)

Nick potts said:


> As i said, a very small minority.


Any numbers on that? Just opposing progress? Or just that you would not need it? Or you feel it can't work?

Sorry @Nick potts  don't attack you personally, just enjoy the debate and try to get to progress for our hobby

As I said, I have no need to prove right. Just want vendors to innovate and bring the hobby forward. If the proposed concept works, and I believe it will,  someone may shake up the current market that seems reluctant to solve hobbyists struggles. Very few businesses that don't deliver customer satisfaction are long term sustainable.


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## Yugang (11 Feb 2022)

foxfish said:


> I am on your side mate


just one hobbyist to support, better than none.

Perhaps some seasoned scientists may step in, to help me understand where I got it wrong. Or study and refine the concept to make it better.

It is remarkable that hobbyists seem more stuck with status quo than vendors 

My aim is bring the idea in public domain, see if it survives and see if it thrives. Exciting discussion! Time will tell who got it right.


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## Hanuman (11 Feb 2022)

Yugang said:


> Specialists on this forum say that hobby grade are not up to standard, need to spend for the industrial or lab grade. 500-1000 USD.


I never said one needs to spend that much. I was stating facts about quality vs price. Most people will be satisfied with cheap regs because most people don't go scaping for many years. After a year or two stop and move on to other things. You can live with such low quality regulators for some time before things go down south.



Nick potts said:


> most will tell you a decent dual-stage hobby reg will work fine.


They do, but most people are not experienced with CO2. With experience they realize buying cheap is not always a good thing. As the say goes, buy cheap, buy twice, buy expensive, cry once.



Nick potts said:


> As i said, a very small minority.


Not among professionals or among those who are keen on always improving efficiency. I know quite a few who only use quality grade regulators. Majority didn't buy new but refurbished which drops the price to around 300/400 usd. But in general yes most people will buy much cheaper regulators then complain down the line about something a few weeks, months, year later. I see it over and over and over again. All facebook aquascape groups I am in are filled with such complains. I see it in all forums as well.


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## ian_m (11 Feb 2022)

My regulator (single stage), with needle valve was £46 in 2012 and still works wonderfully, along with the 22mm inline diffuser. Took a while to get sorted but has been fine ever since, nice green/yellow drop checker all around the tank.

The biggest point of failure I have encountered, in all these years, is the bubble counters.

First "cheapy" one, the plastic bottle, was attacked by CO2 and crazed and shattered. 2kg extinguisher emptied in a couple of days...
2nd one, the plastic pipe clamps fractured, possibly attacked by CO2. 2kg extinguisher emptied in a couple of days...
Eventually settled on JBL bubble counters but again after a year or two:
- The O rings harden up and leak.​- The attach to tank suction cups no longer hold their suction, the rubber hardening probably due to tank light.​
My opinion is KISS, KEEP IT SIMPLE ST*PID, just keep it simple and it works.

Over the years there have been numerous Indiegogo,  kickstarters etc CO2 controllers/meters/tank controllers but I have never seen any product actually produced, delivered at a price point people are willing to pay.

CO2 in water can't be directly measured, you use pH of the water as a proxy measurement (but depends on KH as well), as well as pH probes being notoriously delicate and they are expensive and need calibrating.

Someone did an kickstarter using method similar to drop checker, measure CO2 in air gap above the water, but were unable to get their "so called cheap" CO2 probe to measure low levels of CO2. Issues killing the project were:

Most "cheap" CO2 sensors (say £30) measure up to 10000ppm (10%) really meant for breathing air quality. They don't work down to 30ppm or less. They need dry air.
More sensitive CO2 sensors use infrared sensors, cost £150 odd, but can read low ppm values. Also need dry air to work.
So project got no where.


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## MichaelJ (11 Feb 2022)

Yugang said:


> As a hobbyist I would welcome new solutions for more reliable CO2 management, affordable and easy to operate.
> 
> Now just imagine….
> 
> ...


Hi @Yugang  I like this.  I am not a CO2 user myself, so I am not _invested_  in the current methodologies and I don't understand all the issues either, but merely judging from the amount of people struggling with CO2, there seems to be plenty of need for improving the technology to make it more reliable and easy to apply.  The key component appears to be the ability to quickly, reliably and precisely measure or infer dissolved CO2 at any given time and feed that back to the dosing mechanism (regulator) in order to ensure stable and sufficient delivery.  CO2 sensors for photoacoustic spectroscopy (measuring CO2 levels in air) are fairly cheap, and I bet if demand would be higher for a similar device measuring CO2 levels in water (not relying on pH and KH probes), it would dramatically drive down cost and increase the feasibility of your idea.

Cheers,
Michael


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## Djoko Sauza (11 Feb 2022)

I'm all for evolving our methods of injecting CO2 but I don't think anything involving a pH probe is the solution. It is just not user friendly or reliable.

Buy a quality needle valve, find an injection rate you're happy with and place your bubble counter where you can easily see it when performing daily maintenance tasks such as feeding etc.
It doesn't need to be more complicated than that.

Of course components will break over time, such as all other things in this hobby, just accept that, anticipate it if you can and be ready to deal with the consequences otherwise.

If you come up with something that doesn't involve so many moving parts and electronics then I'm all ears. Until then KISS it is for me.


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## arcturus (11 Feb 2022)

Yugang said:


> So you don't understand the technical concept of my posting.


Would the probe be measuring the water's pH? Would the CO2 injection rate be regulated by the controller? If the answer to these two questions is yes, then you risk injecting a lethal concentration of CO2 if there are variances in dKH (due to water changes and/or changes in carbonate levels in the tank). Or are you assuming that the relationship between dKH and pH in the tank's water will tell you the actual CO2 concentration? It will not. This is why you need a drop checker and not a pH probe to gauge the actual CO2 levels. Or would your device measure the pH in the drop checker instead? That would be an interesting idea, but then how would the system overcome the lag of the drop checker readings? Or are we talking about a sensor to actually measure the actual dissolved CO2 levels? This is why I am not understanding the technical concepts in your proposal 


Yugang said:


> An affordable regulator/needle valve, yet controlled and corrected by the controller and probe.


There are plenty of affordable (~300 EUR) CO2 controllers that use a pH probe to control a CO2 solenoid valve (JBL, Dennerle, Milwaukee, etc.). If you crank up the needle valve and let the controller inject CO2 based on pH readings you risk killing all livestock.


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## Yugang (12 Feb 2022)

Read this morning the replies that came in overnight, and frankly have hardly seen any objection that was not already explained in my first posting. Will answer the most common objections, rather than a one on one debate with some who may have vested interests. I realise I am rocking the boat in the interest of the hobby, but definitely do not want the debate to get personal.

It is common for tech companies to run their innovation projects through 5 or 6 gates/milestones, from gate 1 the initial idea to gate 6 product launch. We are now in a gate 1 situation, where I, or anybody cannot yet be definitively sure if the concept will fly. Indeed, if we now see clear showstoppers it is time to abandon the idea. Otherwise one may want to build some prototype, cost engineering, customer feedback and see if the project makes sense. So let’s handle now some objections or potential showstoppers:

There is no customer need, no market for this new idea

At least a part of the more advanced CO2 users are dissatisfied with hobby grade regulators
Quality regulators (easy to set, stable over time, no surprises after unboxing) would cost 500 USD and up, with little sign that the vendors will address this.
CO2 diffusors come with disadvantages (efficiency, maintenance) that a reactor wouldn’t have
For all users, advanced or not, setting CO2 is a tricky hit and miss business
Using a pH probe and pH/CO2 computer is problematic and expensive

The full set can be bought already for around 140 GBP (check Amazon)
pH probe maintenance is very easy, and guarantees long lifetime
pH probe as spare part is not expensive, just check. You don’t need a lab grade probe, as slightly better than 0.1 pH will do
A pH/CO2 computer works, check also the new ECINU product
Yes, you need to calibrate pH probe, and in my posting I did include drop checker for final call
Too much technology and moving parts

The only moving part is the needle valve on the regulator. Reactor is just pipe with water and bubbles.
pH/CO2 computer already on market for years, successfully used by many hobbyists.
Too expensive

Can use a hobby grade regulator, no need to go to multiples of the price with industrial grade. Stepper motor is cheap
Reactor is a pipe with water
A pH/CO2 controller including probe is sold at 140 GBP, much cheaper than a quality regulator
So now imagine a couple of smart engineers in China (a nod to our EUR/US vendors) who want to run with it, build a prototype, cost engineer and see from there.
*As an advisor, what would be your top 3 arguments to let them stop this project at this first gate?*

As I started this thread, I feel obliged to answer on the top 3 showstoppers that would be brought up with further postings.

As said before, my only aim is to shake the tree and have vendors a bit more responsive and innovative. If I get my industrial grade CO2 regulator with 5 years warranty for 200-300 USD, I would consider that indeed 'KISS' and an attractive alternative to consider - at least for the short term


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## erwin123 (12 Feb 2022)

Technical side
As someone who oversees project managers and business analysts, I can sense that this suggestion is coming from the marketing and sales side rather than the engineering side, and as far as I can see, the assessment of technical feasibility and cost by the engineering has not been done yet.
If this proposal comes to me, I would ask for a report and assessment by my engineering team. This comes even before building the prototype.

Business side
As a tech geek, I wouldn't want to let the lack of customers derail a technologically interesting project, so if the engineers say lets go, I'll say go.  After all, the eventual product might have other applications we haven't thought of.  But as a hobbyist, I doubt this product will be used by those who have small fish tanks and setups with less equipment. Stable CO2 is easy to achieve in a small tank. So that leaves hobbyists with large planted tanks as potential customers, not sure how many.

There should also be assessment of competing products that are doing exactly the same job, get legal to check on patents for CO2 stabilisation etc (there could well be patents for such equipment - maybe there was someone just like Yugang who came first, thought of something, and patented it,  just that it was not viable to commercialize)

Conclusion
Without proper engineering assessment, this is just a request to build a 'magic box'.


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## Yugang (12 Feb 2022)

erwin123 said:


> Technical side
> As someone who oversees project managers and business analysts, I can sense that this suggestion is coming from the marketing and sales side rather than the engineering side, and as far as I can see, the assessment of technical feasibility and cost by the engineering has not been done yet.
> If this proposal comes to me, I would ask for a report and assessment by my engineering team. This comes even before building the prototype.
> 
> ...


Fully agree, indeed 'Gate 1' and next comes more detailed technical/commercial feasibility study  

As a physicist, with analytical/medical instrumentation background, and having several years of experience with all relevant building blocks in my own tank, I'd say that I will be very surprised if it does not work. And it will not be expensive to manufacture.

Just hope that someone takes it up and runs, as a hobby we can benefit from having that option to choose.


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## MichaelJ (12 Feb 2022)

erwin123 said:


> Conclusion
> this is just a request to build a 'magic box'.


Well, that is not an uncommon approach.. and usually the companies that succeed at that are the ones that becomes admired and build products that consumers want...  I've been engaged in R&D my whole working life, associated with companies everyone here would know... and I've lived through a lot of _"requests to build a magic box"_ .... more often than most people appreciate,  it's just this visionary who walks in, in front of a bunch of  scientists and engineers and tell them this is what we are going to do and they will make it happen...

Cheers,
Michael


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## Djoko Sauza (12 Feb 2022)

Injecting CO2 is dangerous so for me the least possible points of failure the better.  An aquarium's dKH (and therefore pH) is affected by many factors, from rocks leaching carbonates to wood and botanicals leaching acids and substrates that can raise or lower pH.
So while using a pH probe may work in some circumstances, in others it may have catastrophic consequences. It would be especially dangerous for beginners that are not aware of chemical reactions in their tank.



Yugang said:


> For all users, advanced or not, setting CO2 is a tricky hit and miss business


Everyone has a choice on how tricky it is. If they want to run their tank on a knife's edge trying to push plant growth to the extreme then CO2 is no more hit and miss than other factors. Everything can cause imbalance and therefore "derail the train", be it ferts, maintenance, CO2 etc.
Since no aquarium is the same, there is no magic formula that will work for everyone. So it _is, _in general, mostly trial and error, with problems being exacerbated/sped up in a high energy system.
Not up to the challenge? Run a medium or low energy system. Sufficient CO2 levels will then not be so hard to mantain consistently. There are beautiful tanks running less than 30ppm CO2.
I do think CO2 problems are more prevalent in tanks using EI since CO2 can easily become your limiting nutrient.

Anyway, if you are running a high energy tank wouldn't pH profiling and reacting to observable CO2 problems or drop checker be preferable to letting a pH probe handle such an important job?

To keep it short: I don't like having a pH probe dictate the rate of CO2 injection due to reliability issues, even if some aquarists successfully use them. It is a potentially point of failure that I'd rather not have.


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## Wookii (12 Feb 2022)

Interesting thought process here. I agree with what most folks have posted, a pH controller measuring the tank water is a recipe for disaster. 

That said, I’m surprised a manufacturer hasn’t come up with a probe that sits in a specific isolated solution, and uses air gap diffusion much like a drop checker. These are available at the professional level:






						CO₂NTROL Dissolved Carbon Dioxide Sensors | Process Analytics | Hamilton Company
					

CO₂NTROL is a Solid-State Sensor that directly measures DCO₂ and provides maintenance free, real-time, and in-line control of this important critical process parameter. Get automated control that enables increased titer, better batch-to-batch reproducibility, and more consistency from R&D to...




					www.hamiltoncompany.com
				




Cost and almost complete lack of customers will of course be the reason this product isn’t available at the hobby level.


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## Stu1407 (12 Feb 2022)

Wookii said:


> Interesting thought process here. I agree with what most folks have posted, a pH controller measuring the tank water is a recipe for disaster.
> 
> That said, I’m surprised a manufacturer hasn’t come up with a probe that sits in a specific isolated solution, and uses air gap diffusion much like a drop checker. These are available at the professional level:
> 
> ...


Although I have no idea of the actual cost of the commercial unit, I do wonder if lack of customers would be an issue. Reef keepers seem to have no problem spending this and upwards Reef Factory KH Keeper Plus


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## Hanuman (13 Feb 2022)

Stu1407 said:


> Reef keepers seem to have no problem spending this and upwards Reef Factory KH Keeper Plus


That's because the cost of all the fish, coral they got in their tanks. Fresh water tanks keepers have no where near the investment of reef tank keepers and so spending all that much money doesn't make much economic sens unless you are making a business out of it.


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## erwin123 (13 Feb 2022)

MichaelJ said:


> Well, that is not an uncommon approach.. and usually the companies that succeed at that are the ones that becomes admired and build products that consumers want...  I've been engaged in R&D my whole working life, associated with companies everyone here would know... and I've lived through a lot of _"requests to build a magic box"_ .... more often than most people appreciate,  it's just this visionary who walks in, in front of a bunch of  scientists and engineers and tell them this is what we are going to do and they will make it happen...
> 
> Cheers,
> Michael



CEO: Can I have a magic box that removes algae from my tank but leaves the plants healthy?
R&D: We tried but failed, but the prototype produces lots of cool looking bubbles!
CEO: Good enough for me!

I'm still waiting for an anti-algae magic box!


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## Hanuman (13 Feb 2022)

To me that's the problem. People want to have it all without thinking and experiencing and hope for a magic box.


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## Yugang (13 Feb 2022)

Djoko Sauza said:


> Injecting CO2 is dangerous so for me the least possible points of failure the better.


Ultimately it will be a personal choice. One may always take the stairs, worried about the points of failure of the elevator. I would suggest the risks can be assessed better after engineering has been done, and based on test result in the real world.



Djoko Sauza said:


> An aquarium's dKH (and therefore pH) is affected by many factors, from rocks leaching carbonates to wood and botanicals leaching acids and substrates that can raise or lower pH.





Yugang said:


> Calibration is done while running in aquarium water, using a drop checker to set the target pH, and then ‘never’ look at it again.


Ok, let’s calibrate a bit more frequently than ‘never’. Drop checker is always there, so you use that as you third level of safety.



Djoko Sauza said:


> So while using a pH probe may work in some circumstances, in others it may have catastrophic consequences. It would be especially dangerous for beginners that are not aware of chemical reactions in their tank.


Let’s go back one century, and find very similar quotes on using cars replacing horse. Our todays car has thousands of points of failure, faces many potential lethal risks and is even more dangerous to drive when not experienced. Should't we be more focussed to improve the concept, rather than taking it down even before engineering has looked at it?



Wookii said:


> I’m surprised a manufacturer hasn’t come up with a probe that sits in a specific isolated solution, and uses air gap diffusion much like a drop checker.


Is a beautiful concept, but will have slow reaction time and will be impractical for most control loops. As a final safety device, switch off solenoid if something is wrong, may be very useful and take away a lot of the concerns articulated in this thread.



Wookii said:


> I agree with what most folks have posted, a pH controller measuring the tank water is a recipe for disaster.


Have you, or others opposing the idea already in it conceptual phase actually ever used a pH probe/controller in your tank, and experienced how it works in real life? Have you noted that I propose still using drop checker to calibrate? Have you considered modifications to the concept to make it more to your liking, perhaps the ‘electronic drop checker’ as a safety switch?


New CO2 Regulator
They are on the right track, but failed to make it even smarter and cost effective.


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## Yugang (13 Feb 2022)

*Yugang low tech CO2 dream regulator*

Motivated by the outpouring of support for innovation in this thread, and new friends, I want to bring something entirely different.

We forget the idea of an expensive industrial grade (>500 USD) or lab grade (>1000 USD) regulator, for achieving stability. Go really simple and low cost, but with unparalleled stability and ease of use. In fact we forget the needle valve, and perhaps even the single or double stage pressure reducer.

We are going to use a micro CO2 gas nozzle, essentially a small hole in a piece of metal, ceramics, or similar technological solution. The size of the hole, and incoming gas pressure will determine how much CO2 gas flows through. Think of it as a needle valve, but no longer adjustable.

The vendor would sell us a housing, with a set of nozzles. Each nozzle has its own bubbles per second: for example 0.5 bps, 1 bps, 2, 4, 8, 16, 32.

After purchase, we mount the smallest nozzle in our housing and see what it does during the day on our drop checker. Not enough? - go one nozzle bigger and repeat.

Now with this idea, we can also construct a housing in which several nozzles can be placed in parallel. For example 2 bps nozzle + 8 bps nozzle will give 10 bps into the tank.

Each nozzle position in the housing can have its own solenoid (super cheap, safe and by default in off-position), so that there is the option to have this low tech regulator controlled by any pH/CO2 controller.

Depending on the technology applied for manufacturing the nozzles, perhaps it is even possible to work without a pressure reducer and operate the nozzles straight on the CO2 pressure from the cylinder. That would be the most simple, stable and affordable solution

I believe it serves our hobby to bring ideas to the public domain (if not patented already it is from here prior art and accessible to all vendors). I have no personal gain from this, may aim is to serve the hobby and shake things up a bit.

Cheers
YUGANG
(a.k.a. CJR)


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## Stu1407 (13 Feb 2022)

Hanuman said:


> That's because the cost of all the fish, coral they got in their tanks. Fresh water tanks keepers have no where near the investment of reef tank keepers and so spending all that much money doesn't make much economic sens unless you are making a business out of it.


Having kept a reef or fowlr tank for more than 25 years I would disagree. Myself and others that I have met over that time tend to be far more motivated by ease of use and time saved which tends to lead to better water management. At the moment having spent £300 plus on plants alone I wouldn't mind spending more on reliable equipment to look after my investment.


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## Hanuman (13 Feb 2022)

Stu1407 said:


> Having kept a reef or fowlr tank for more than 25 years


I have spend 0 years keeping reef tanks but I see prices of salt water fish and corals vs fresh water fish and plants, and they are two worlds very much apart. A plant can be propagated. A salt water fish when he dies, well his dead. If you paid a fish 500/1000 usd or more, well you are very careful how you take care of your tank. Plus having talked to multiple reef tank keepers I have been told that they can go south MUCH faster than a fresh water tank. Fresh water tanks can be left unatended for much longer than a reef tank. All this implies equipment, time and money.

You can spend a lot of money in fresh water tanks as well if you want but a lot of that money is not a requirement to keep a tank alive. 


Stu1407 said:


> At the moment having spent £300 plus on plants alone I wouldn't mind spending more on reliable equipment to look after my investment.


Good but I doubt you would need to spend as much money than on a reef tank just to keep a tank stable and thriving.


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## KirstyF (13 Feb 2022)

Whilst I would agree that the market for a ‘perfect’ Co2 system at a higher cost may not be huge (in the first instance) I wouldn’t be convinced that it doesn’t exist. I’ve spent £300 on my current Co2 set up (not including cylinders) and closer to £400 on Gyres just to improve flow. 

So, ignoring the technicalities of creating such a system, I think the bigger challenge may be confidence. There is something somewhat scary about the concept of leaving the fate of your fish (and your plants) in the hands of a techie gizmo, despite the fact that, in reality, we already do this to some extent, just as soon as we add Co2 to a tank. 

Current methods, however, are tried and tested and points of possible failure are known and understood (though not always entirely avoidable). 

A new piece of technology would require enough people to adopt it at the higher price point, shout about its reliability/efficacy and create a larger ‘market’ in order for price points to reduce.

I wonder whether the Co2 issues that people experience are adequate to drive this process. 

How many people go through 3 Co2 systems that have all failed. How many people buy cheap needle valves, have failures, but then resolve just by getting a better needle valve. 

However, how many people would be prepared to pay out more for a system that had proved to be reliable, effective and that would genuinely manage their Co2 for them, with minimum input, less stress and worry and great results?  

IMO, at the right price (albeit a higher price) there would certainly be a market for that. 

Ask anyone who ever purchased something with ADA written on it. People will clearly pay ‘over the odds’ for a good bit of kit.


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## arcturus (13 Feb 2022)

Yugang said:


> pH probe maintenance is very easy, and guarantees long lifetime
> pH probe as spare part is not expensive, just check.


The cheaper plastic probes often used in the hobby rely on liquid or gel type electrolytes.  These will not have a long lifetime submerged in liquids due to the continuous osmosis of the electrolyte. The pH probes designed for continuous readings are expensive. The frequent replacement of pH probes is actually the major running cost of pH/CO2 computers, that the manufacturers (ECINU, INTAQO, JBL, Dennerle, ...) obviously forget to explain. This extra cost does not fit in the product strategy you are aiming at, unless you also decide to ignore this detail.



Yugang said:


> A pH/CO2 computer works, check also the new ECINU product
> pH/CO2 computer already on market for years, successfully used by many hobbyists.


Sorry, but this is incorrect. CO2 computers that rely on pH readings of the tank water do not work unless you assume that the water parameters are stable. These controllers determine CO2 based on pH and KH. This works if and only if (1) KH is stable, and (2) pH is only changing as a consequence of CO2. But these two assumptions do not apply in a tank and that is why the classical KH/pH tables will not help you determining the actual CO2 concentration. It is possible to keep KH stable (like in some marine tanks), but then we would be dramatically (and unnecessarily) increasing costs and complexity.






There are basically two groups of users of CO2 controlling systems:

Users who regulate the needle valve to specify the CO2 injection rate for a specific set of water parameters, and then use the pH computer to switch off  the solenoid in case the pH level goes below a given threshold. The CO2 computer is only used as a kind of safety device because the CO2 concentration is determined exclusively by the needle valve regulation. But this also means you do not need the CO2 computer at all to control the CO2 concentration...
Users who rely entirely on the CO2 computer for CO2 injection. In this case, the CO2 computer controls the solenoid according to a target derived from the pH of the tank water. With this system, the CO2 concentration can reach virtually any level in case the solenoid is kept open. This means that if the pH increases due to factors unrelated to CO2 concentration, then the CO2 computer may inject lethal levels of CO2. The same will happen with variations in KH.



Yugang said:


> Yes, you need to calibrate pH probe, and in my posting I did include drop checker for final


The drop checker would not stop the CO2 computer from injecting too much CO2, would it?

This is why I am not understanding the actual goals of your "dream machine". Isn't your "dream machine" just a normal CO2 regulator with a good quality needle valve, complemented with a good set of instructions on how to actually profile and calibrate CO2 injection (which means putting in the garbage the pH/KH tables that are part of the documentation of the current CO2 controllers)?


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## Yugang (13 Feb 2022)

@arcturus I may react later in detail, but you are basically stating that pH/CO2 controllers do not work. Have you actually used one?

I used my pH/CO2 controller for years without any issue. I bought it for less than the 140 GBP I referred to. I used the first probe for years, continuously and without any problem. I replaced my probe once, I believe I paid some 20 GBP for that, when I moved house and did not realise I needed to keep the probe in the proper wet condition during storage.



arcturus said:


> Isn't your "dream machine" just a normal CO2 regulator with a good quality needle valve, complemented with a good set of instructions on how to actually profile and calibrate CO2 injection (which means putting in the garbage the pH/KH tables that are part of the documentation of the current CO2 controllers)?


The fundamental part of the dream machine is that it measures the pH in the reactor exit, not in the tank, and has a feedback loop to a continuously variable CO2 injector, unlike the controllers that are now in the market. With due respect, I believe you still don’t understand the technology and miss the entire concept including its  user benefits.


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## Yugang (14 Feb 2022)

I like UKAPS most for learning about plants, and for the inspiration from fellow hobbyists. After a lively discussion this weekend, it’s a good time for me to step back from the tech and let this thread do its work - as the ideas in public domain may, or may not, have some impact on how vendors innovate on CO2 and bring our hobby forward.

The essential point of my two contributions is that technical solutions that rely on extremely precise mechanics (quality grade regulators), pushed to and beyond its limits, will always be expensive ( and/or unreliable), especially considering the budgets of hobbyists . So we need some good new ideas to escape from this dilemma.

I did not mean to upset our vendors. They do great work for the hobby. On purpose I did not mention any brand, and decided to not write down some of my thoughts regarding their marketing message or business model. I brought ideas in public domain as that will give a level playing field for those who see the value and decide to take them up

Thank you, and as I warned in my first posting  


Yugang said:


> please skip and proceed to next topic, or continue at own risk


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## ian_m (14 Feb 2022)

Wookii said:


> That said, I’m surprised a manufacturer hasn’t come up with a probe that sits in a specific isolated solution, and uses air gap diffusion much like a drop checker. These are available at the professional level:
> 
> 
> 
> ...



These are no good for fish tank CO2 injection as the lowest they read is 0.5% (500ppm), suitable for bio-reactors etc. These won't even read air at 400ppm, yet alone down to 30ppm and lower we require. 

To make this project get beyond stage 1, you would need to "design & invent" a suitable probe that reads accurately and reliably do down to 30ppm in "contaminated " water, as currently no such probe exists, which is why pH level is used as a proxy to CO2 level.

Again, as stated a quality regulator (mine was £46), current super quality regulator prices are £100 -£150, set up correctly will yield 30ppm injection levels regardless of water quality, pH probe calibrations, any other probes, computers etc. CO2 turns on, levels rises to 30pmm. Job done.


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## arcturus (14 Feb 2022)

Yugang said:


> @arcturus I may react later in detail, but you are basically stating that pH/CO2 controllers do not work. Have you actually used one?


Yes, a JBL pH controller. It can "work" if the water has plenty of buffering capacity but, in my experience, you can get a stabler CO2 concentration throughout the photo period using a needle valve alone (and note that the JBL controller has hysteresis control). It will not work if (1) the dKH is low, (2) dKH is variable, or (3) pH changes due to factors unrelated to CO2. I personally know one case where all livestock was killed due to the controller injecting too much CO2 after a water change due to the tap water parameters. This was also a hot topic a while ago in my local fish club when Seiryu stones started messing up with these controllers due to the release of carbonates. As I said in my other posts, a pH controller can work if you are able to control water parameters. But it is not a panacea.



Yugang said:


> I used my pH/CO2 controller for years without any issue. I bought it for less than the 140 GBP I referred to. I used the first probe for years, continuously and without any problem. I replaced my probe once, I believe I paid some 20 GBP for that, when I moved house and did not realise I needed to keep the probe in the proper wet condition during storage.


If you have such a positive experience with a cheap pH controller and cheap probes, then why are you proposing this "dream machine"? It seems to me that you already have your found your dream machine, right?

However, in the real world, the JBL probe costs ~90 EUR and has an expected life span of ~12 months. The pH probe from the Dennerle controller costs approximately the same and has similar life span.

I actually built a WiFi-enabled continuous water temperature and pH reader (not controller) using a Raspberry Pi some years ago. There are plenty of pH measurement kits for the Arduino and Pi. I remember I bought a pack of 3 pH probes at aliexpress for something like 20 EUR. Each of the probes lasted a couple of months. I then bought a better quality probe for submersible use that lasted a couple of years.


Yugang said:


> The fundamental part of the dream machine is that it measures the pH in the reactor exit, not in the tank, and has a feedback loop to a continuously variable CO2 injector, unlike the controllers that are now in the market. With due respect, I believe you still don’t understand the technology and miss the entire concept including its  user benefits.


First, you have to understand I am not trying to undermine your idea. But I would like to discuss the actual problems with this approach. You have not yet explained how such device could achieve its intended purpose without measuring the actual dissolved CO2 concentration in the water. Measuring pH at the reactor's exit tells you absolutely nothing about the CO2 concentration in the tank water. All you have presented so far is a variant of existing pH controllers that rely on proxy CO2 measurements based on tank water. These controllers have known limitations that you are not bringing into the discussion. The fundamental problem of these controllers is not the CO2 injection mechanism but the CO2 measuring mechanism.

Second, we would need to explain what is the actual benefit of such system compared to a system that relies exclusively on a needle valve. We can achieve stable CO2 concentrations with the latter, without the multiple points of failure and complexity of the former. What is sorely missing in CO2 injection systems is the lack of basic knowledge on how to tune and operate them.


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## Hanuman (15 Feb 2022)

arcturus said:


> What is sorely missing in CO2 injection systems is the lack of basic knowledge on how to tune and operate them.


I summarized that with a rougher statement earlier:


Hanuman said:


> To me that's the problem. People want to have it all without thinking and experiencing and hope for a magic box.


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## Yugang (15 Feb 2022)

arcturus said:


> Yes, a JBL pH controller. It can "work" if the water has plenty of buffering capacity but, in my experience, you can get a stabler CO2 concentration throughout the photo period using a needle valve alone (and note that the JBL controller has hysteresis control). It will not work if (1) the dKH is low, (2) dKH is variable, or (3) pH changes due to factors unrelated to CO2. I personally know one case where all livestock was killed due to the controller injecting too much CO2 after a water change due to the tap water parameters. This was also a hot topic a while ago in my local fish club when Seiryu stones started messing up with these controllers due to the release of carbonates. As I said in my other posts, a pH controller can work if you are able to control water parameters. But it is not a panacea.
> 
> 
> If you have such a positive experience with a cheap pH controller and cheap probes, then why are you proposing this "dream machine"? It seems to me that you already have your found your dream machine, right?
> ...



I should not make this thread unnecessarily long and complicated with a detailed technical debate with contributors who don’t believe in it, or vendors who will naturally be defensive and lay down a marketing  smoke screen. It is good enough if only a few understand the concept, how it will work under realistic assumptions and proper user operation, and  develop it for the benefit of the hobby.

With two decades of sales and marketing management in high tech, I know it’s tough and sometimes you have to go and fight the threat out there to protect your company’s interest. So despite the debate, and some of my feedback on postings, I very much respect these people doing their job.



arcturus said:


> a pH controller can work if you are able to control water parameters. But it is not a panacea.


Correct. pH/CO2 controllers are already in the market, including premium brands, and they are not a panacea.



arcturus said:


> pH controllers that rely on proxy CO2 measurements


Indeed, pH is a proxy for CO2 concentration. Unless you’re doing strange things with your water hardness, like adding acid or baking soda, dKH is not changing much between calibrations and certainly not changing fast.



arcturus said:


> If you have such a positive experience with a cheap pH controller and cheap probes, then why are you proposing this "dream machine"?





Yugang said:


> I don’t like sending alternating waves of high CO2 enriched water and not-enriched water into the tank, concerned about BBA. After several years, no longer using mine






arcturus said:


> Measuring pH at the reactor's exit tells you absolutely nothing about the CO2 concentration in the tank water. All you have presented so far is a variant of existing pH controllers that rely on proxy CO2 measurements based on tank water





arcturus said:


> Second, we would need to explain what is the actual benefit of such system compared to a system that relies exclusively on a needle valve. We can achieve stable CO2 concentrations with the latter, without the multiple points of failure and complexity of the former


Respectfully, I believe you either do not understand the systems feedback loop concept yet, or you feel it is so relevant that you go for the marketing smokescreen.

ECINU is already out there with a high quality pH/CO2 controller and very attractive user interface. However, the proposed solution in my first posting takes it from a naked pH/CO2 controller, to an integrated system concept using a CO2 reactor and smart feedback loop that will bring benefits that ECINU cannot claim.



arcturus said:


> a system that relies exclusively on a needle valve. We can achieve stable CO2 concentrations with the latter, without the multiple points of failure and complexity of the former.


In this case ....


Yugang said:


> Yugang low tech CO2 dream regulator


.... may be your favourite. No points of failure, unparalleled reliability and cheap. If that were on the market 😃


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## MichaelJ (15 Feb 2022)

Yugang said:


> Thank you, and as I warned in my first posting



Hi @Yugang  Well, I am a fan of your idea! ... and I'll bet you a good bottle of red wine (of your choice)  that what you envision  will happen eventually!

The tech is just not there yet in an affordable package... the solution to the problem is likely a sort of non-dispersive infrared absorption (NDIR) device... those are not cheap, but nothing is ever cheap from the onset. If you can reliable measure CO2 and feed that measurement to a valve (regulator) you have your solution. No reliance of pH or KH measurements etc.

Not sure why people are pushing back on your idea... instead of latching on to it and trying to build on it. 

Cheers,
Michael


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## Yugang (15 Feb 2022)

I make one more note, as said before I think it is good for me to step back from the tech discussion. With some, I may agree to disagree - no worry and time will tell if current vendors, or perhaps some disruptive outsiders provide the hobbyist with new CO2 options.

My current thought, also digesting the feedback, is that the Yugang CO2 dream system will work in real life situations (despite industry insiders spreading smoke and fear), it will not be expensive to manufacture, but it will need to build trust in the community. Initially perhaps a niche product, longer term may be a different story - engineered cost down and trusted by more hobbyists for being reliable. In my opinion, the dream system’s natural home will be integrated with canister filters.

My personal real favourite for short term is the Yugang low tech dream regulator. It has no moving parts, is inherently stable and cheap. It takes us from the unattainable wish to have an expensive industrial grade CO2 needle valve, to an entirely different low cost solution that will outperform the needle valve for the specific requirements of our hobby.


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## Yugang (15 Feb 2022)

Thank you @MichaelJ - I needed some support from fellow hobbyists, it feels a bit lonely  


MichaelJ said:


> I'll bet you a good bottle of red wine (of your choice)


Now you're getting in dangerous territory


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## MichaelJ (15 Feb 2022)

Yugang said:


> (despite industry insiders spreading smoke and fear)


Oh you mean the ones that have more to loose than gain? 


Yugang said:


> Thank you @MichaelJ - I needed some support from fellow hobbyists, it feels a bit lonely


Well, you are most certainly welcome!  And as I've mentioned in a previous post, I've been around the block a couple of times help _building magic boxes_ ... it was especially memorable when people said something was impossible, not feasible or even the dumbest thing they ever heard of... 


Yugang said:


> Now you're getting in dangerous territory


haha... I knew it! (... my disclaimer: as long as it its something from Napa valley...)  

Cheers,
Michael


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## Hanuman (15 Feb 2022)

As much as I appreciate the desire to have a machine that does it all for you, I don't see this happening (at least not during our life time) for the following reasons and at the expected reliability:

1 . We know only one way to deliver a gas at a certain pressure, and that is through a regulator. There as plenty of regulators out there, good and bad but let's say for a moment that we are able to produce a quality/reliable 2-stage regulator small enough that can be integrated in your dream system. This would require the removal of analogue gauges replaced by internal electronic gauges  to measure pressure accurately. Accurate digital gauges are expensive. A redesign of the regulator as we know it would also be required. R&D = cost up. Now comes the delivery system;

2. We don't know any other way to deliver a gas at a specified rate other than through a needle valve (or flow meter which incorporates a needle valve). In order for you to deliver consistently and accurately a gas you need a high precision needle valve SPECIALLY in our hobby where flow is ridiculously low. Precision needle valves are complex in nature and require high tech manufacturing, hence their price tag. In your system we would need an electronically controlled needle valve. Guess what, they exist and are more expensive than high end, precision needle valves. But since we want all to be in a reasonably small package some more R&D would be required here.

3. Now comes the CO2 measurement. Best bet we have so far are probes. PH measurement are unreliable by nature and degrade with time. There are other ways to measure CO2 like the CO2NTROL but it would need to be adapted to our hobby to be able to measure such low CO2 concentrations. Technology can still evolve in this area. In any case an interface would be required to monitor the measuring's device accuracy and lifespan. More R&D.

4. Now package the whole shebang in one integrated box that would simply attach to the CO2 canister with let's say a simple human interface where one would only adjust CO2 ppm desired. This would be relatively easy in relation to the above, but still would require some more R&D for proper integration and usability.

Now the real problem is not the technology since we are technologically capable of producing such device. The problem is the actual cost of producing it. For manufacturers of the above hardware, the aquarium hobby is a ridiculously small market. To produce what you want it would require a good amount of money for R&D but also to produce high end hardware. In my rough estimates such dream box in today's situation wouldn't come for less than 8-10k usd simply because the aquarium hobby is a niche market. For price to lower considerably to the point where you want, it would require a massive market, in the millions of potential customers, which we know is not going to happen.

Don't get me wrong, I would be happy to have such device, but I am realistic also and know what is possible and what's not in the present state of affairs.


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## Yugang (15 Feb 2022)

Hanuman said:


> As much as I appreciate the desire to have a machine that does it all for you, I don't see this happening (at least not during our life time) for the following reasons and at the expected reliability:
> 
> 1 . We know only one way to deliver a gas at a certain pressure, and that is through a regulator. There as plenty of regulators out there, good and bad but let's say for a moment that we are able to produce a quality/reliable 2-stage regulator small enough that can be integrated in your dream system. This would require the removal of analogue gauges replaced by internal electronic gauges  to measure pressure accurately. Accurate digital gauges are expensive. A redesign of the regulator as we know it would also be required. R&D = cost up. Now comes the delivery system;
> 
> ...



I'll keep my reply short. With respect, you seem not to grasp the concept of feedback and control loops which enable lower precision of individual components that build the system. Furthermore, note that pH/CO2 controllers are already in the market for our hobby.



Hanuman said:


> This would require the removal of analogue gauges replaced by internal electronic gauges to measure pressure accurately.





Hanuman said:


> In order for you to deliver consistently and accurately a gas you need a high precision needle valve SPECIALLY in our hobby where flow is ridiculously low.


No need for both. In fact the control loops enables a lower precision of the components compared to traditional set up. This will significantly lower manufacturing costs, for those who understand the technical concept.

As you may have noted in my previous post, I think Yugang low tech dream regulator, perhaps with three parallel nozzles, may be an even better solution, integrated within the dream machine, than a conventional needle valve with stepper motor. The controller just opens and closes nozzles through their solenoids, and for those with safety concerns the max CO2 flow through such system will be limited whatever happens.



Hanuman said:


> PH measurement are unreliable by nature and degrade with time


Tell that to established vendors marketing pH/CO2 controllers, and their customers. Not correct. I also very much like @MichaelJ idea, so we should not necessarily limit ourselves to pH probes but should explore other sensors as well to drive the feedback loop to the injector.



Hanuman said:


> Don't get me wrong, I would be happy to have such device


Thank you. Or perhaps the Yugang low tech dream regulator as a first step


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## Hanuman (15 Feb 2022)

ian_m said:


> current super quality regulator prices are £100-£150,


Not to argue, but are you referring to a single or a double stage reg? If the later, to my knowledge there is no super quality double stage regulator at that price point. Perhaps you are referring to CO2Art or the like double-stage regulators? If that is the case that is not what I call a super regulator.  Can it deliver CO2 at a decent flow rate for a year or so? maybe. Is it accurate, so so. Is it enough for our purposes? For the majority of people it will. Also, single stage regulators are more robust as there are less parts involved.

All I know is that cheap regs that I have owned always have had a problem at some point in time. The 3 I have had showed issues in less than a year. In my case I had to change the bubble counter/non-return valve (twice), the needle valve and the solenoid rod. One let water in the "needle valve", the other clearly was changing the flow rate from morning to evening, the last would not shut down fully letting CO2 through. You could argue that these are problems not related to the regulator itself, but reality is that cheap regulators also use lower quality internal diaphagrams which will leak at some point, and I know a few people who have had that happen to them with el-cheepo regs straight out of the box.

Ultimately what I want to say is that, Can I get away with cheap regs? Answer, definitely. The real question is, Will I trust it? Answer, no.


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## Yugang (15 Feb 2022)

Hanuman said:


> Not to argue, but are you referring to a single or a double stage reg? If the later, to my knowledge there is no super quality double stage regulator at that price point. Perhaps you are referring to CO2Art or the like double-stage regulators? If that is the case that is not what I call a super regulator.  Can it deliver CO2 at a decent flow rate for a year or so? maybe. Is it accurate, so so. Is it enough for our purposes? For the majority of people it will. Also, single stage regulators are more robust as there are less parts involved.
> 
> All I know is that cheap regs that I have owned always have had a problem at some point in time. The 3 I have had showed issues in less than a year. In my case I had to change the bubble counter/non-return valve (twice), the needle valve and the solenoid rod. One let water in the "needle valve", the other clearly was changing the flow rate from morning to evening, the last would not shut down fully letting CO2 through. You could argue that these are problems not related to the regulator itself, but reality is that cheap regulators also use lower quality internal diaphagrams which will leak at some point, and I know a few people who have had that happen to them with el-cheepo regs straight out of the box.
> 
> Ultimately what I want to say is that, Can I get away with cheap regs? Answer, definitely. The real question is, Will I trust it? Answer, no.


Good points. As you have also pointed out before, in another thread, current quality regulators depend on extremely precise mechanics pushed to its limits of design and manufacturing tolerance. This is because they need to handle very low flows, be adjustable and be stable and use the traditional operating principle.

If we go out of the box and think about the nozzles in my proposed Yugang low tech regulator, we make things much more easy and much more reliable. For aquaria in fact better suited than a traditional regulator, whatever the price that one is bought for.


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## jaypeecee (15 Feb 2022)

arcturus said:


> This is why you need a drop checker and not a pH probe to gauge the actual CO2 levels. Or would your device measure the pH in the drop checker instead? That would be an interesting idea, but then how would the system overcome the lag of the drop checker readings? Or are we talking about a sensor to actually measure the actual dissolved CO2 levels?


Hi @arcturus & Everyone,

I mentioned very recently, perhaps on another thread, that I have experimented with using a pH electrode dipped into a 4dKH solution. See link to picture below. The solution is contained in a small tube, at the bottom of which is a semi-permeable membrane that allows CO2 gas to pass through it. The bottom/tip of this assembly is then inserted into the tank water. As CO2 quickly diffuses through the membrane, this is detected by the pH electrode. I found that it worked a treat for CO2 entering the tube. Response time was a few minutes. But, when CO2 concentration dropped in the aquarium water, response time was sluggish. I suspect this could be improved.






						Why Advise A 1pH Drop?
					

Hi Folks,  I don't understand why a 1pH drop is advised when setting up a profile for injected CO2. For example, if the water KH is 4dH and the starting pH is 7.3, the CO2 concentration will be approximately 6 ppm. But, after a 1pH drop to 6.3, the CO2 concentration will be a staggering 60 ppm...



					www.ukaps.org
				




JPC


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## hypnogogia (15 Feb 2022)

I'm a huge fan of technology, particularly where it can make life easier, and therefore welcome the discussion of how to use technology to manage CO2 in our aquariums.  Let's face it, I want to enjoy my aquarium, not get hung up with monitoring and adjusting.

One thing that I don't understand about the dream machine is why measure pH at the outlet?  Whether we measure in tank or the outlet, the pH is still subject to influences other than CO2 concentration. Further, getting it right at the outlet won't take into account CO2 loss at the aquarium surface.  Whilst the measurement at outlet might suggest 30ppm, that doesn't mean it will be 30ppm in the tank.  I seem to remember @jaypeecee suggesting combining a pH probe suspended in 4dKH solution with a semi permeable membrane to allow CO2 to enter the 4dKH solution, and all this suspended in the tank.  Essentially an electronic drop checker.  Might developing this idea further add to the Yugang CO@ Dream Machine?


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## Yugang (15 Feb 2022)

jaypeecee said:


> Hi @arcturus & Everyone,
> 
> I mentioned very recently, perhaps on another thread, that I have experimented with using a pH electrode dipped into a 4dKH solution. See link to picture below. The solution is contained in a small tube, at the bottom of which is a semi-permeable membrane that allows CO2 gas to pass through it. The bottom/tip of this assembly is then inserted into the tank water. As CO2 quickly diffuses through the membrane, this is detected by the pH electrode. I found that it worked a treat for CO2 entering the tube. Response time was a few minutes. But, when CO2 concentration dropped in the aquarium water, response time was sluggish. I suspect this could be improved.
> 
> ...





Wookii said:


> I’m surprised a manufacturer hasn’t come up with a probe that sits in a specific isolated solution, and uses air gap diffusion much like a drop checker


These are very useful thoughts, and I consider it the ultimate safety check for in-tank use. For in the reactor, the control loop needs relatively good reaction times. So the combination of the two, could really make sense


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## Yugang (15 Feb 2022)

hypnogogia said:


> I'm a huge fan of technology, particularly where it can make life easier, and therefore welcome the discussion of how to use technology to manage CO2 in our aquariums.  Let's face it, I want to enjoy my aquarium, not get hung up with monitoring and adjusting.
> 
> One thing that I don't understand about the dream machine is why measure pH at the outlet?  Whether we measure in tank or the outlet, the pH is still subject to influences other than CO2 concentration. Further, getting it right at the outlet won't take into account CO2 loss at the aquarium surface.  Whilst the measurement at outlet might suggest 30ppm, that doesn't mean it will be 30ppm in the tank.  I seem to remember @jaypeecee suggesting combining a pH probe suspended in 4dKH solution with a semi permeable membrane to allow CO2 to enter the 4dKH solution, and all this suspended in the tank.  Essentially an electronic drop checker.  Might developing this idea further add to the Yugang CO@ Dream Machine?





Yugang said:


> The function of this system would be to blow a flow of water enriched with a targeted ppm CO2 (stabilised, not alternating) into the tank:


Only if you measure in the reactor will you have quick enough feedback to the control loop to create a really nice constant flow. If you have a 5-10 times hourly turnover of your aquarium water, with a perfectly stabilised CO2 ppm from the reactor, you will soon achieve stability in your tank as well. Calibration,  also compensating for outgassing losses in the tank, is done with your drop checker in the tank as final judge.

Hope this helps


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## jaypeecee (15 Feb 2022)

hypnogogia said:


> Might developing this idea further add to the Yugang CO@ Dream Machine?


Hi @hypnogogia 

I think there is scope for development/improvement. It's almost certainly possible to obtain a better semi-permeable membrane than the one I used - probably about five years ago.

JPC


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## Hanuman (15 Feb 2022)

Yugang said:


> f we go out of the box and think about the nozzles


I'll be honest but I am not sure I understand this nozzle thing. Isn't that what a needle valve does? A needle valve is basically a needle that goes in an out of a hole (excuse the pun) and let's gas through more or less depending how much you screw or unscrew. In other words, a nozzle that can be adjusted infinitely better than just a pre manufactured nozzle with a hole.


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## Yugang (15 Feb 2022)

Hanuman said:


> I'll be honest but I am not sure I understand this nozzle thing. Isn't that what a needle valve does? A needle valve is basically a needle that goes in an out of a hole (excuse the pun) and let's gas through more or less depending how much you screw or unscrew. In other words, a nozzle that can be adjusted infinitely better than just a pre manufactured nozzle with a hole.


I can't explain it more clearly than in my original post.  Each different nozzle has a different bps, for example a smaller or larger hole in a piece of metal. No adjustment, no moving parts. You place one or more nozzles in your housing, lock it and ready to go. Nothing can go wrong and it will be perfect stability and safety. If the nozzle that you have mounted now does not give you what you want to see on your drop checker, too low CO2 ppm, then you dismount and replace by one size bigger nozzle.


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## Yugang (15 Feb 2022)

Hanuman said:


> nozzle thing







'Artist impression' of what a nozzle looks like, just because I am bad in drawing things on my PC.  No needle, no moving parts. Just a small sized hole though which fluid or gas flows. The size and length of the hole, with gas pressure, will tell you the flow and thus CO2 bubble per second.


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## Hanuman (15 Feb 2022)

I know what a nozzle is, just didn't understand how you were planing on integrating that.

If I may, that nozzle idea seems pretty strange and unpractical to me and way more fiddly than simply turning a dial. You said no moving parts, but here you go having to change nozzles if it doesn't suit your CO2 requirement.  Understand that CO2 injected in a tank will vary basically virtually for every single tank out there because every tank is different, water parameters are different for everyone, volume of water is different for everyone, plant mass is different, aeration is different etc etc etc. One would need a large amount of nozzles with a very minute difference between them just to make sure at least one of them fits your needs. Then what happens when plant mass increase? You need to change the nozzle again? See where I am going? A manual needle valve eliminates that entirely and the only way I see to automate that part without user input is what I proposed earlier, an electronic needle valve that could adjust automatically according to ones needs in terms of CO2 ppm.


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## Yugang (15 Feb 2022)

Hanuman said:


> I know what a nozzle is, just didn't understand how you were planing on integrating that.
> 
> If I may, that nozzle idea seems pretty strange and unpractical to me and way more fiddly than simply turning a dial. You said no moving parts, but here you go having to change nozzles if it doesn't suit your CO2 requirement.  Understand that CO2 injected in a tank will vary basically virtually for every single tank out there because every tank is different, water parameters are different for everyone, volume of water is different for everyone, plant mass is different, aeration is different etc etc etc. One would need a large amount of nozzles with a very minute difference between them just to make sure at least one of them fits your needs. Then what happens when plant mass increase? You need to change the nozzle again? See where I am going? A manual needle valve eliminates that entirely and the only way I see to automate that part without user input is what I proposed earlier, an electronic needle valve that could adjust automatically according to ones needs in terms of CO2 ppm.





Yugang said:


> The vendor would sell us a housing, with a set of nozzles. Each nozzle has its own bubbles per second: for example 0.5 bps, 1 bps, 2, 4, 8, 16, 32.
> 
> After purchase, we mount the smallest nozzle in our housing and see what it does during the day on our drop checker. Not enough? - go one nozzle bigger and repeat.
> 
> Now with this idea, we can also construct a housing in which several nozzles can be placed in parallel. For example 2 bps nozzle + 8 bps nozzle will give 10 bps into the tank


This is the idea. You get roughly the bps that you want by combining 2 or three nozzles in parallel, and after that have for years a stable CO2 supply.


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## arcturus (15 Feb 2022)

Yugang said:


> Indeed, pH is a proxy for CO2 concentration. Unless you’re doing strange things with your water hardness, like adding acid or baking soda, dKH is not changing much between calibrations and certainly not changing fast.


In the real world, dKH can change fast. What about Seiryu stones? Or any other stone that releases carbonates? You can experience an increase of 0.5 - 1.0° _per day_ with such stones. What about the KH buffering introduced by aquasoils, is it also irrelevant?  In my region tap water is extracted from three major sources: a forested area fed by underground aquifers, a marshland close to a river, and a mountain area nearby. The GH and KH can change by ~10° overnight depending on the proportion of these water sources.


Yugang said:


> Respectfully, I believe you either do not understand the systems feedback loop concept yet, or you feel it is so relevant that you go for the marketing smokescreen.


I think you are making too many assumptions about other people's knowledge. You should be the one explaining the concepts you are proposing. Instead, you throw buzzwords into the discussion and then say other people lack knowledge because they are not understanding your ideas. This is not how a discussion works...


Yugang said:


> ECINU is already out there with a high quality pH/CO2 controller and very attractive user interface.


Apart from the UI, can you explain what are the actual differences between ECINU, INTAQO, JBL and Dennerle controllers, just to name a few? What makes ECINU a "high quality" controller?


Yugang said:


> However, the proposed solution in my first posting takes it from a naked pH/CO2 controller, to an integrated system concept using a CO2 reactor and smart feedback loop that will bring benefits that ECINU cannot claim.


I do not understand how your "smart" feedback loop will work with a single pH sensor at the CO2 reactor's exit, given that you would not be controlling for several other variables that will affect the actual CO2 concentration in the water. Your feedback loop only works if we make a number of invalid assumptions regarding the proxy measurement of CO2.


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## ian_m (15 Feb 2022)

Yugang said:


> The size and length of the hole, with gas pressure, will tell you the flow and thus CO2 bubble per second.


If only it where that simple, it would have been done .

Orifices are not really used for precision gas control (fluid control is a lot easier) due to the following:

The gas flow is proportional to (hole size)^2, which means small holes, for suitable low rate CO2 injection have to be very accurate (and expensive). A 10% error in hole size would lead to 20% increase in flow and bye bye fish,
Another issue is flow is inversely proportional to square root on temperature, a 20'C change in temperature will give 10% change in gas flow (lower temp higher flow).
There are also different "flow regimes", a high pressure regime and low pressure regime both give difference relationships between pressure, flow, hole size, temperature and gas type.
Flow depends on pressure difference either side, at least one side should be regulated and "low pressure" eg 10bar, not 55bar CO2 cylinder pressure. Oh you need a regulator...so why not use a regulator.



> >If only it where that simple, it would have been done .


Actually correcting myself, it has been done. Very cheap so called regulators, like the ones on disposable CO2 containers are in fact not really regulators but either a metal sponge block or an orifice (like you suggest). They just restrict the flow of the gas, but are generally on 14bar CO2 containers, are renowned for being notoriously unreliable,  extremely difficult to set and suffered from end of tank dump. End of tank dump occurs when pressure drops sufficiently low, the metal sponge block or an orifice, no longer offers resistance to flow and the container empties out into tank. This generally will not gas your fish as CO2 remaining in the tank is generally small, but if using a 2kg CO2 container the remaining volume is large and you gas your fish.


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## arcturus (15 Feb 2022)

Yugang said:


> Only if you measure in the reactor will you have quick enough feedback to the control loop to create a really nice constant flow. If you have a 5-10 times hourly turnover of your aquarium water, with a perfectly stabilised CO2 ppm from the reactor, you will soon achieve stability in your tank as well. Calibration,  also compensating for outgassing losses in the tank, is done with your drop checker in the tank as final judge.


1. An efficient CO2 reactor dissolves most of the injected CO2 in the water. Such reactors often operate on a bypass at a relatively low flow (200-400 l/h) to maximize dissolution. In medium and larger sized tanks you would need several CO2 reactors in parallel to handle a flow of 5-10x of the total water volume.

2. Due to the efficiency of a reactor, the pH at the reactor's outlet is mostly independent of the CO2 concentration in the tank water. This measure would enable us to determine the CO2 injection rate, not the CO2 concentration in the tank. There will be slight pH variations on the reactor's pH water output depending on its input, but you would need an extremely accurate and high precision pH probe to register those variations and an error in this measurement could have lethal consequences.


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## Hufsa (15 Feb 2022)

Yugang said:


> (despite industry insiders spreading smoke and fear)


I dont understand this part, who are you referring to @Yugang ?

Ive been following along with the thread, I like that you are thinking outside the box and sometimes a fresh outlook on how to do things is all that is needed to set something new into motion. I cant say I am seeing any unreasonable pushback, @arcturus has asked some questions about how certain mechanisms would work, many of the questions are ones I share as well and would like answered. I dont really think it is fair to dismiss them as not understanding, when there are at least a handful of us who are not quite sure how you would go about implementing certain things. Shouldnt you explain it rather than dismiss it? Someone critiquing your idea is not necessarily someone trying to keep you down, they could be trying to help you refine the idea by pointing out potential flaws. A bunch of "Yes-men" dont actually contribute anything useful to a project. 
Everyone has their own experience with usage of products and perceived safety and so on, but there is only one reality and some mechanisms work a certain way and we cant really get around that. If something is not possible to do using current means then we must acknowledge that and agree that either we have to invent a new way to get around the issue or adjust the idea to correspond.

I hope you wont take this the wrong way, you know that I appreciate you and your contributions to the forum @Yugang 
Im just not seeing smokescreens and haters


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## Hanuman (15 Feb 2022)

In the meantime and to lighten up the atmosphere I got my CO2 cylinder hydrostatically tested. End of parenthesis.


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## arcturus (15 Feb 2022)

Hanuman said:


> In the meantime and to lighten up the atmosphere I got my CO2 cylinder hydrostatically tested. End of parenthesis.
> 
> View attachment 182752View attachment 182753View attachment 182754


 How long is the new certificate valid over there? Around here, the re-certification is usually only worth for larger bottles as it costs roughly the same as a new 2Kg cylinder


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## Yugang (15 Feb 2022)

arcturus said:


> 1. An efficient CO2 reactor dissolves most of the injected CO2 in the water. Such reactors often operate on a bypass at a relatively low flow (200-400 l/h) to maximize dissolution. In medium and larger sized tanks you would need several CO2 reactors in parallel to handle a flow of 5-10x of the total water volume.


This does not demonstrate that you understand CO2 reactors. It all depends on tuning the reactor dimensions with the flow rate. Very basic technology, and can be scaled up without any issue.



arcturus said:


> 2. Due to the efficiency of a reactor the pH at the reactor's outlet is mostly independent of the CO2 concentration in the water. There will be slight pH variations on the pH water output depending on the input but you would need an extremely accurate and high precision pH probe to register those variations.


This must be new physics.

@arcturus - if you find the idea irrelevant and not feasible, just ignore this thread from now on please

If perhaps you are in the CO2 business, wish innovation will not  go too fast for your liking, my humble suggestion would be you take a deep breath, then get a good physics and engineering team and run before outsiders do it and disrupt your market. 

Sorry for being a bit harsh, but I like to step back from the tech discussion and I start to be a little annoyed with the smoke screens - that I believe are not a sign interests of the hobbyist are really respected. 

Future will tell who is right, can we agree to disagree?


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## Yugang (15 Feb 2022)

Hufsa said:


> I dont understand this part, who are you referring to @Yugang ?
> 
> Ive been following along with the thread, I like that you are thinking outside the box and sometimes a fresh outlook on how to do things is all that is needed to set something new into motion. I cant say I am seeing any unreasonable pushback, @arcturus has asked some questions about how certain mechanisms would work, many of the questions are ones I share as well and would like answered. I dont really think it is fair to dismiss them as not understanding, when there are at least a handful of us who are not quite sure how you would go about implementing certain things. Shouldnt you explain it rather than dismiss it? Someone critiquing your idea is not necessarily someone trying to keep you down, they could be trying to help you refine the idea by pointing out potential flaws. A bunch of "Yes-men" dont actually contribute anything useful to a project.
> Everyone has their own experience with usage of products and perceived safety and so on, but there is only one reality and some mechanisms work a certain way and we cant really get around that. If something is not possible to do using current means then we must acknowledge that and agree that either we have to invent a new way to get around the issue or adjust the idea to correspond.
> ...


I understand where you're coming from @Hufsa. I am not going to suggest I 100% know who is representing vested business interests, but from the defensive approach to a constructive   new proposal for our hobby I can have a strong indication.  Much of the opposition does not have the clarity that is to be expected after very detailed explanations and evidence. Now this can be that people still do not understand, or that they do not want to understand, or that they just have a vested interest to confuse the argument.

I have no doubt that several contributions are really to try and learn, try to understand, and I appreciate that. We're here not a tech forum after all.

As said before I deeply respect people who stand up and defend their business, so for me nothing personal. Yet at some point, when I aim to bring some fresh innovation that comes with some disruption I can't continue to argue with people who act under a nick name, assuming that they still don't understand it and only want to learn. Of course, I can expect that industry pushes back with all means they have, I would be surprised (unless my proposals are irrelevant) if they didn't

I do not want to play on the person, in fact I consider my mission achieved and want to step back. Time will tell if my 2 contributions will have meaningful benefits to the hobby


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## arcturus (15 Feb 2022)

Yugang said:


> This does not demonstrate that you understand CO2 reactors. It all depends on tuning the reactor dimensions with the flow rate. Very basic technology, and can be scaled up without any issue.


There is nothing special about scaling the reactors up apart from the costs. Otherwise, you would easily find affordable, efficient, high flow CO2 reactors in the market.


Yugang said:


> This must be new physics.


I will be waiting for you to produce a chart that shows the pH readings at the reactor's outlet for an input of water with dissolved CO2 between 0-40 ppm. After you produce the data, we can start talking about physics.



Yugang said:


> @arcturus - if you find the idea irrelevant and not feasible, just ignore this thread from now on please


With all due respect, last time I checked this was a public forum. It is you who are not willing to openly discuss your ideas.


Yugang said:


> perhaps you are in the CO2 business, wish innovation will not  go too fast for your liking, my humble suggestion would be you take a deep breath, then get a good physics and engineering team and run before outsiders do it and disrupt your market.
> Sorry for being a bit harsh, but I like to step back from the tech discussion and I start to be a little annoyed with the smoke screens - that I believe are not a sign interests of the hobbyist are really respected.


Do you really think you would have representatives of the CO2 or the aquarium industry wasting their time with coffee table discussions in internet forums? Do you really think what you are proposing is some kind of innovative patent-worthy idea? I think we are really getting into the Dunning-Kruger realm here...


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## Yugang (15 Feb 2022)

arcturus said:


> There is nothing special about scaling the reactors up apart from the costs. Otherwise, you would easily find affordable, efficient, high flow CO2 reactors in the market.
> 
> I will be waiting for you to produce a chart that shows the pH readings at the reactor's outlet for an input of water with dissolved CO2 between 0-40 ppm. After you produce the data, we can start talking about physics.
> 
> ...


If you are not involved in CO2 business in any way, I do sincerely apologize if my tone has not been appropriate. It would help if you could confirm though.



arcturus said:


> Otherwise, you would easily find affordable, efficient, high flow CO2 reactors in the market


I can show you how to do it. Modify an AquaMedic, it is so simple you can't believe it.



arcturus said:


> With all due respect, last time I checked this was a public forum. It is you who are not willing to openly discuss your ideas.


Absolutely, and if you're just an interested hobbyist you have my apologies for being a little harsh.



arcturus said:


> Do you really think you would have representatives of the CO2 or the aquarium industry wasting their time with coffee table discussions in internet forums? Do you really think what you are proposing is some kind of innovative patent-worthy idea? I think we are really getting into the Dunning-Kruger realm here...


I am perfectly fine if you dismiss the ideas, no worry. I have nothing to gain from this, act not under my personal name, and only want to bring some progress to the hobby. Time will tell what it brings and we may agree to disagree now.

Sorry @arcturus, nothing personal from my side, irrespective if you appear to be defending a business (which I would respect) or just here as a eager to learn hobbyist. Challenge is good, and the debate is worth it as long as we stay respectfull and friendly on this forum.

I will try to step back from this tech discussion, hope that reading it was fun.


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## arcturus (15 Feb 2022)

Yugang said:


> If you are not involved in CO2 business in any way, I do sincerely apologize if my tone has not been appropriate. It would help if you could confirm though.


I do not understand why do you think you would have industry representatives participating in such discussions in public internet forums...

Manufacturers producing technical devices for "high tech" freshwater tanks are addressing a microscopic niche area. CO2 controllers are virtually irrelevant from a business perspective. If the industry could actually develop effective and "intelligent" low-cost solutions for CO2 injection you would have them on the market already. The reason why you don't have them is because they would require quite expensive equipment (especially because we are measuring very low concentrations of dissolved CO2) to actually improve the currently available controllers, which are nothing but a pH probe connected to computer controlling a solenoid valve.


Yugang said:


> I can show you how to do it. Modify an AquaMedic, it is so simple you can't believe it.


Yes. there are plenty of CO2 reactors based on fluidized media reactors. You can build a much cheaper version by connecting in series a few large diameter water pipes with fluidized media inside them. But reactors lose dissolution efficiency with increasing water flow rate, hence the usual bypass.



Yugang said:


> Absolutely, and if you're just an interested hobbyist you have my apologies for being a little harsh. I am perfectly fine if you dismiss the ideas, no worry. I have nothing to gain from this, act not under my personal name, and only want to bring some progress to the hobby. Time will tell what it brings and we may agree to disagree now.
> 
> Sorry @arcturus, nothing personal from my side, irrespective if you appear to be defending a business (which I would respect) or just here as a eager to learn hobbyist. Challenge is good, and the debate is worth it as long as we stay respectfull and friendly on this forum.


I am not trying to dismiss your ideas but to discuss them. And I honestly fail to understand what type of business I would be defending since I am actually saying that existing CO2 controllers based on pH have critical limitations.

Are you aware of any cheap, accurate and precise dissolved CO2 measuring device (such as non-dispersive infrared absorption sensors) to replace the pH probe? I am not. Maybe those are easy and cheap to build. If that is the case, then you have a business opportunity that might want can explore. But your ideia is based on pH probes! Anyway, it would be great if you found a way to tackle the challenges of CO2 measurement and control using the classical proxy measurement of pH, which has fundamental flaws due to lack of control over variables related to dissolved solids and other water parameters. If we ignore the cost factor from this discussion altogether, then we can simply replace the pH probe with a dissolved CO2 measuring device, reprogram the controller for the new sensor while keeping the rest of the CO2 injection tech. Problem solved


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## ian_m (15 Feb 2022)

arcturus said:


> I will be waiting for you to produce a chart that shows the pH readings at the reactor's outlet for an input of water with dissolved CO2 between 0-40 ppm. After you produce the data, we can start talking about physics.


Ooooo I can answer this one.....the physics is really simple and easily charted/graphed.

Here it is the chart you asked for 0-40ppm region ringed. pH along the top, ppm CO2 in the table. 
Just make sure your kH is fixed (preferably above 4 to provide a bit of buffering), you are using "carbonated water" (non of this yucky contaminated fish water stuff) and you are good to go. Inject CO2 until pH is your desired level. Simple.





I suspect you can all see this issue with this method.


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## arcturus (15 Feb 2022)

ian_m said:


> Ooooo I can answer this one.....the physics is really simple and easily charted/graphed.
> 
> Here it is the chart you asked for 0-40ppm region ringed. pH along the top, ppm CO2 in the table.
> Just make sure your kH is fixed (preferably above 4 to provide a bit of buffering), you are using "carbonated water" (non of this yucky contaminated fish water stuff) and you are good to go. Inject CO2 until pH is your desired level. Simple.
> I suspect you can all see this issue with this method.


Exactly. This only works in controlled environments. And measuring the pH at the reactor outlet is even worse. The output value would be fully dependent on KH buffering. One can measure pH at the reactor to estimate the amount of injected. Even better to use a solution like @jaypeecee <tried out> to actually measure the CO2 through ga diffusion, and not through water pH. But this value is not relevant to determine the concentration of CO2 in the tank - for example, two similar tanks with the same injection but with different rates of gaseous exchange would end up with different CO2 ppm in the water.


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## arcturus (15 Feb 2022)

jaypeecee said:


> Hi @hypnogogia
> 
> I think there is scope for development/improvement. It's almost certainly possible to obtain a better semi-permeable membrane than the one I used - probably about five years ago.


Some <industry solutions> also use a membrane and then measure the gas through the <dispersion of (infra-red) light>.  Others use <a Severinghaus electrode>. These approaches might provide faster readings than the pH change in the KH solution.


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## ian_m (15 Feb 2022)

arcturus said:


> Some <industry solutions> also use a membrane and then measure the gas through the <dispersion of (infra-red) light>. Others use <a Severinghaus electrode>. These approaches might provide faster readings than the pH change in the KH solution.


Infra-red are only good for "higher values" of CO2, reading down to 100ppm for expensive ones.
The other solutions given involve a permeable "delicate" silicone membrane the CO2 diffuses through. Use to be plastic membrane, but modern are silicone. They also have multiple compensation electrodes (which is why they can give a pH & temperature value as well) that have to be combined/calculated before a CO2  value can be found. Also suffer from misreading due to ions, I think phosphate is such an interfering ion, which is a shame as this will be present in a planted tank. And finally....not cheap....


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## jaypeecee (15 Feb 2022)

Hi @arcturus 

I became aware of the Severinghaus electrode shortly after my setup. That's one of the reasons why I decided not to pursue a patent application. I was under the impression that my setup was similar to the Severinghaus electrode but I've never seen one. Using dispersion of IR light is likely to fall way outside any aquarium hobbyist's budget. But, I think my basic idea could be improved. Some discussion with a membrane manufacturer would be an obvious starting point. But, now that I'm retired, it's not another job that I would want to take on board.

JPC


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## jaypeecee (15 Feb 2022)

ian_m said:


> The other solutions given involve a permeable "delicate" silicone membrane the CO2 diffuses through.


Hi @ian_m 

My 'prototype' shown in the picture also uses a silicone (PDMS) membrane. It's the obvious choice of material having particularly high permeability to CO2.

JPC


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## ian_m (15 Feb 2022)

jaypeecee said:


> My 'prototype' shown in the picture also uses a silicone (PDMS) membrane. It's the obvious choice of material having particularly high permeability to CO2.


The reason I know a bit about this, is I was approached a while ago about someone wanting to start a kickstarter/indiegogo project for fish tank CO2 monitoring/controlling.  They wanted rough idea costs and timescales for the processor/controller side of the project, about £150 (in small quantities) and probably about 6 or more months development time, as was quite a software element as all was controlled via wireless web front end.

The CO2 sensor was supposedly the clever bit, sensing CO2 in gas gap above the tank water, BUT no sensor was located or had been invented yet that would work in such "horrible conditions". All sensors investigated had issues, IR was not sensitive enough (also massively affected by water vapour), glass/plastic/silicone bulb sensors were not cheap but sensitive enough BUT all suffered issues, worked fine wet, worked fine dry but not humid and/or covered in drops, effected by light getting in, low level voltages present so interference and/use of low noise PTFE cable (@ £5 per meter),  acid/alkaline drops of liquid on the sensors could stop them reading, some required temperature compensation, in liquid sensors required pH compensation, some didn't like phosphates or nitrates in the liquid they came into contact with. Was all a mess and project stopped at initial investigation stage.....before any serious money or time was spent. I think someone who was also party to this "idea" involved in initial ideas did start crowdfunding (not the Flelix controller), but didn't make the project startup and project faded away.


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## jaypeecee (15 Feb 2022)

Hi @ian_m 

Thanks for that. Good to hear what went on behind the scenes. None of what you have said comes as a surprise to me. The investment required would have been greater than the hoped-for revenue. And, the timescale would no doubt have been prohibitive for a company that was little more than a wishful start-up.

JPC


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## sparkyweasel (15 Feb 2022)

arcturus said:


> If the industry could actually develop effective and "intelligent" low-cost solutions for CO2 injection you would have them on the market already.


We wouldn't make much progress if everyone thought that you can't make anything new, because it must be impossible or it would have been done before.


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## MichaelJ (15 Feb 2022)

arcturus said:


> I think we are really getting into the Dunning-Kruger realm here...


Speaking from "Mt. Stupid" here , as I don't have any practical experience with CO2, but this NDIR sensor will measure down to the 0-50 ppm range at a fairly high precision. I didn't look into the pricing etc., but with high enough demand and a "cheaper packaging" cost might be practical. Just throwing it out there for the wolves to tear apart, if you can! 

So now someone  just need to get one of those probes, tear it apart, build the necessary electronics around it and and hook it up to a regulator as a proof of concept! 

Anything else?

Cheers,
Michael


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## Yugang (15 Feb 2022)

ian_m said:


> If only it where that simple, it would have been done .
> 
> Orifices are not really used for precision gas control (fluid control is a lot easier) due to the following:
> 
> ...



Physists with knowledge about managing gas flow know how to create a really small 'leak' of gas. In my early days in university I did some plasma physics, so that is the community who may have some answers.

Of course, we can always argue that new concepts can not work. And of course, as hobbyist we know everyting is fine and we have really no issues with our needle valves, their temperature dependence, their precise and effortless setting, their stability over time or costs.

I believe I know how to make a 'nozzle', with a smart technology that is quite obvious and cheap as well. I am not sure if there is prior art (probably yes), if I want to bring this piece on this forum into public domain, if it is more logical for vendors who want to push the envelope to find a suitible technology partner, or if  on this particular aspect I research IP protection.

I see all the pushback on dream machine, but let smart readers in US, Europe or Asia make up their mind and see if it works as a business idea. I like the Yugang low tech regulator even more, assuming somebody perfects the nozzles, as it will brings unparalleled simplicity and reliability to the hobby.


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## jaypeecee (15 Feb 2022)

Hi @MichaelJ 

Yes, what you have brought to our attention is certainly interesting. But, I would estimate the cost of this probe as prohibitively expensive for the aquarium hobbyist.

JPC


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## MichaelJ (15 Feb 2022)

jaypeecee said:


> Hi @MichaelJ
> 
> Yes, what you have brought to our attention is certainly interesting. But, I would estimate the cost of this probe as prohibitively expensive for the aquarium hobbyist.
> 
> JPC


Hi @jaypeecee   Well, I will ask them... The probe might be expensive, but that doesn't necessarily reflect the actual cost of production and material... I wouldn't be surprised if the reseller price for this product is 20x the actual cost to build the product... But anyway, someone should investigate and take it from there... Imagine if something could be build that is slightly less precise, but precise enough,  and at a much lower cost?  Eventually your just going to look at an integrated product that may retail for a few hundred bucks... still a lot of money yes, but not prohibitively.

I wonder if anyone have a ballpark figure of how many hobbyists are injecting CO2 ? In the US alone there are roughly 12.5 million households that keep aquariums. What percentage would be injecting CO2?  ... its a small number, but how small?  

Cheers,
Michael


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## Hanuman (15 Feb 2022)

arcturus said:


> If the industry could actually develop effective and "intelligent" low-cost solutions for CO2 injection you would have them on the market already.





sparkyweasel said:


> We wouldn't make much progress if everyone thought that you can't make anything new, because it must be impossible or it would have been done before.


That's a generic statement. What is said is pretty much the truth. This hobby is simply not a target for big tech companies to do R&D and spend millions for a high tech low cost, cheap CO2 solution as envisioned by the OP.


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## jaypeecee (15 Feb 2022)

Hi Folks,

I wonder if it would be possible to take advantage of the fact that pressurised gas, when escaping through a tiny orifice, creates ultrasonic energy? This very principle is used for detecting gas leaks. In fact, having once got fed up using the soapy water method, I considered buying such a leak detector. Perhaps the same principle could be used in the Yugang CO2 Dream Machine? For my current needs, I'll stick with the conventional glass DC. Perhaps it's not so bad after all.

JPC


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## Yugang (15 Feb 2022)

arcturus said:


> I do not understand why do you think you would have industry representatives participating in such discussions in public internet forums...


Quite the opposite, I believe it is extremely useful for industry representatives to be on this forum. I also very much like all your helpfull contributions to UKAPS over the past period.

I admit, a lost some sleep last night and felt that I had been too harsh to @arcturus , if indeed I was talking to a fellow hobbyists who is just like me trying to learn and find new ways for the hobby. I am serious here, don't get me wrong. 
I also very much respect @Hufsa contributions to this forum, both in content and in style. Feedback from @Hufsa  I take very serious and will correct myself



Yugang said:


> If you are not involved in CO2 business in any way, I do sincerely apologize if my tone has not been appropriate. It would help if you could confirm though


I believe this invitation for clarity was not replied by @arcturus . 
It is relevant for me, because it makes a big difference if I am talking hobby-science with a fellow hobbyist who didn't understand the concept yet (and to whom I would owe an apology for my tone), or taking to a CO2 business executive who deliberaty argues so as to protect the status quo and business intests

@arcturus before I discuss any further tech with you, and not knowing if your aim is to learn, to build on good ideas, or to confuse - could you clarify please? Much appreciated!


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## Yugang (15 Feb 2022)

Hanuman said:


> This hobby is simply not a target for big tech companies to do R&D and spend millions for a high tech low cost, cheap CO2 solution as envisioned by the OP.


I agree to some extent, yet Chinese tech startups are more creative, find the right technology partners, manage costs down and are global champions in production.


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## Hanuman (16 Feb 2022)

I have not seen a single high tech innovation in our hobby. Not one. All that has been done is repackaging of well known technology at a cheaper cost.


Yugang said:


> I believe this invitation for clarity was not replied by @arcturus .
> It is relevant for me, because it makes a big difference if I am talking hobby-science with a fellow hobbyist who didn't understand the concept yet (and to whom I would owe an apology for my tone), or taking to a CO2 business executive who deliberaty argues so as to protect the status quo and business intests
> 
> @arcturus before I discuss any further tech with you, and not knowing if your aim is to learn, to build on good ideas, or to confuse - could you clarify please? Much appreciated!


You are being overly paranoid and borderline arrogant here. Your question could be virtually directed to anyone who has contributed to this thread, myself included. Why corner a specific user? 🤷‍♂️ You shouldn't be targeting people like that because you didn't like what the person presented as an opinion. This is a public forum and anyone should be free to present their opinion without being talked harshly because of what their job is or because of their affiliation to a company. Maybe the guy works for a CO2 related company, maybe not, so what? Or maybe you are working for a company with specific vested interests? So what? No matter the case you should be happy if someone in the industry at least takes the time to respond to your ideas. I notice that you seem to dismiss what many people say, even those with years of experience so I wonder what's the point in sharing your ideas in the first place.

I don't see push back in your dream machine, I see people with doubts exposing what they already know and presenting counter ideas. You should take the best of those.


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## arcturus (16 Feb 2022)

Yugang said:


> @arcturus before I discuss any further tech with you, and not knowing if your aim is to learn, to build on good ideas, or to confuse - could you clarify please? Much appreciated!


If I made any comment which seemed to add nothing but confusion then I apologize, because that was not the intent. I said in the beginning of this discussion that I share the goals of this "dream machine" (who wouldn't?) But then I raised questions about its feasibility, because, from your description so far, the system sounds like a variant of the existing pH-based CO2 controllers and does not seem to address their fundamental limitations. The interesting discussion so far in this whole thread is about the feasibility of using other types of CO2 measuring devices instead of pH devices, like the one that @jaypeecee actually tested out. But I have seen no actual contribution to this discussion from you side, since you do not answer the most basic open questions. So, it is me who is actually confused by your aim. Since you started the thread, I had the (wrong) expectation that you would like to discuss the challenges of overcoming the issues of CO2 measurement. 


Yugang said:


> I believe this invitation for clarity was not replied by @arcturus .


???


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## arcturus (16 Feb 2022)

MichaelJ said:


> Hi @jaypeecee   Well, I will ask them... The probe might be expensive, but that doesn't necessarily reflect the actual cost of production and material... I wouldn't be surprised if the reseller price for this product is 20x the actual cost to build the product... But anyway, someone should investigate and take it from there... Imagine if something could be build that is slightly less precise, but precise enough,  and at a much lower cost?  Eventually your just going to look at an integrated product that may retail for a few hundred bucks... still a lot of money yes, but not prohibitively.


The few prices I have seen so far are very high, but these are lab sensors. But I agree that the cost of building the product is a fraction of its actual cost. 


MichaelJ said:


> I wonder if anyone have a ballpark figure of how many hobbyists are injecting CO2 ?


I guess a small percentage of the hobbyist keeping aquascapes, which are a small percentage of the hobbyist keeping aquariums...


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## Yugang (16 Feb 2022)

arcturus said:


> If I made any comment which seemed to add nothing but confusion then I apologize, because that was not the intent. I said in the beginning of this discussion that I share the goals of this "dream machine" (who wouldn't?) But then I raised questions about its feasibility, because, from your description so far, the system sounds like a variant of the existing pH-based CO2 controllers and does not seem to address their fundamental limitations. The interesting discussion so far in this whole thread is about the feasibility of using other types of CO2 measuring devices instead of pH devices, like the one that @jaypeecee actually tested out. But I have seen no actual contribution to this discussion from you side, since you do not answer the most basic open questions. So, it is me who is actually confused by your aim. Since you started the thread, I had the (wrong) expectation that you would like to discuss the challenges of overcoming the issues of CO2 measurement.
> 
> ???


So I feel less concerned that I may have misunderstood where you are coming from. If you were indeed just a fellow hobbyist with an interest in technology, no business interest, you would have confirmed this after me asking you twice.

@arcturus don't misunderstand me, I have been managing high tech marketing and sales for many years, know how challenging these roles are. So you have my respect as a person and as a professional. Yet you must understand that my replies are influenced by the background and agenda of the person I am talking with. I know very well how to lay down a smoke screen, confuse the argument pretending you do not fully understand - I did it too when necessary to protect my business.

I just do not want to play the chess game with you too long, just seeing for example how you are now confusing the argument about reactors. You will not be convinced on this forum, whatever long replies I write on confused technical arguments. Let's agree to disagree, and let time tell if some of the ideas materialise for our hobby


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## Yugang (16 Feb 2022)

arcturus said:


> I guess a small percentage of the hobbyist keeping aquascapes, which are a small percentage of the hobbyist keeping aquariums..


I have no data, but was under the impression that a very significant number of aquarium hobbyists are using CO2. Do I misunderstand? Is our hobby indeed largely low tech?


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## arcturus (16 Feb 2022)

Yugang said:


> So I feel less concerned that I may have misunderstood where you are coming from. If you were indeed just a fellow hobbyist with an interest in technology, no business interest, you would have confirmed this after me asking you twice.


I considered so far everyone on this forum to be fellow hobbysts... you are the first exception to this rule so far! All the best!


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## Yugang (16 Feb 2022)

arcturus said:


> I considered so far everyone on this forum to be fellow hobbysts... you are the first exception to this rule so far! All the best!


I am really sorry to hear that.

I hope you will not underestimate or deny opportunities for innovation in your business, this is really why I wanted to bring new ideas in public domain. 
Seeing how much pain hobbyists have even with pricey regulators, I felt I needed to think out of the box and apply some of my professional experience to the hobby
I do apologize to you and fellow UKAPS members if I have upset you.


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## MichaelJ (16 Feb 2022)

Yugang said:


> I have no data, but was under the impression that a very significant number of aquarium hobbyists are using CO2. Do I misunderstand? Is our hobby indeed largely low tech?


At least for the US: According to the American Pet Products Association roughly 12.5 million households in the US alone are keeping aquariums (A fair share would be marine tanks)...  I would think the percentage injecting CO2 in one or more tanks is probably very, very low.  But it is anyones guess what the percentage might be...

Cheers,
Michael


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## Yugang (16 Feb 2022)

MichaelJ said:


> At least for the US: According to American Pet Products Association roughly 12.5 million households in the US alone are keeping a aquariums (A fair share would be marine tanks)...  I would think the percentage injecting CO2 in one or more tanks is probably very, very low.  But it is anyones guess what the percentage might be...
> 
> Cheers,
> Michael


This could be nice for a poll, feel that my view of our hobby, the percentage of high tech tanks, might need some correction.


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## MichaelJ (16 Feb 2022)

Yugang said:


> This could be nice for a poll, feel that my view of our hobby, the percentage of high tech tanks, might need some correction.


UKAPS is probably quite disproportionate when it comes to the amount of CO2 users. Which probably have something to do with all the really knowledgeable experts on CO2 we have here - there are not _that_ many other places to go for advice on CO2 related issues.

Cheers,
Michael


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## Yugang (16 Feb 2022)

MichaelJ said:


> UKAPS is probably quite disproportionate when it comes to the amount of CO2 users. Which probably have something to do with all the really knowledgeable experts on CO2 we have here - there are not _that_ many other places to go for advice on CO2 related issues.
> 
> Cheers,
> Michael


That could very well be true, and just your question makes me doubt my own assumptions.

I guess some of the CO2 professionals have some good market data?


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## KirstyF (16 Feb 2022)

I’m not a techie expert here but, if I’m understanding this concept correctly, this system seems to be a PH controller with two primary differences:

1 - rather than switching Co2 on and off like a traditional controller, it would instead dial the Co2 up or down as needed to maintain a consistent ph measurement

2 - the ph probe would be at the reactor outlet rather than in the tank. 

To help me understand your concept better, could you confirm what other core differences there would be compared to traditional ph controller system, if any.

If the above 2 suggested differences are correct, could you confirm your perceived benefits.

1 - I caught that you feel up/down may create improved consistency over on/off particularly in regard to BBA. Was there anything else I’ve missed. Lots I’m sure!! 

2 - is it your belief that measuring at the reactor outlet would also create better consistency than measuring in tank and, if so, how? 

I ask because I feel that what you are proposing is an enhanced ph controller and therefore a direct comparison to the existing technology in this field would be relevant and perhaps exploration of the current weaknesses of those systems ultimately offers a better ‘magic box’. 

Many people are uncomfortable with ph controllers for reasons other than just consistency so to genuinely move a new innovation forward in that area, those limitations could be explored too. I think suggestions of using alternate methods of measurement i.e measuring actual dissolved Co2 rather than measuring PH is actually a potentially very valid point.

And, as per my previous response, I think there is likely a potential market for safe and consistent Co2 control. 

If I might also add, from a non-biased position, I do feel maybe it is somewhat unfair to assume that anyone on the forum has an agenda. They may agree or disagree and everyone is influenced by their areas of knowledge, experience and expertise, including yourself of course, but its entirely possible that they may just consider your proposition to be flawed and, right or wrong, that opinion should not IMO bring a persons integrity into question.


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## Djoko Sauza (16 Feb 2022)

arcturus said:


> guess a small percentage of the hobbyist keeping aquascapes, which are a small percentage of the hobbyist keeping aquariums...


There are plenty of fish keepers with planted aquariums (rather than "aquascapes", if the line can be drawn somewhere) who also use CO2 for improved plant growth.

Since there are many more fish keepers than aquascapers, they surely represent a big share of the total CO2 users.


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## arcturus (16 Feb 2022)

Djoko Sauza said:


> There are plenty of fish keepers with planted aquariums (rather than "aquascapes", if the line can be drawn somewhere) who also use CO2 for improved plant growth.
> 
> Since there are many more fish keepers than aquascapers, they surely represent a big share of the total CO2 users.


Agree! Planted aquarium is a much better term than aquascape.


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## Yugang (16 Feb 2022)

@KirstyF  thank you for these questions, happy to clarify as much as I can

Allow me to start with an analogon of the control principle of CO2,  just to give some new fresh perspective.






We are building a Thermal Bath, in the middle of icy mountains. We have a deep well, from which we can pump up hot, really hot water to warm our pool to a comfortable 28 degrees. 2 engineering firms pitch for their solution:

Engineer 1 will place a thermometer somewhere in the pool, switches on the pump and injects the really hot well water in the pool where it will eventually mix with the colder water and bring the thermometer to 28 degrees. From then on will continue reading temp in the pool, and turn hot water pump on and off to blow new hot water into the pool intermittently
Engineer 2 will build a reactor vessel in which he mixes hot well water with pool water, makes sure the temperature in the vessel is always exactly 28 degrees (or perhaps 30), and pumps this stabilised water into the pool with a 5-10 times hourly pool volume rate.
So the question would be:

Is it solution 1 or 2 that is more comfortable for the bath guests?
If engineer 2 is forced to place his thermometer far away in the pool, can he still manage his steady temperature from the mixing vessel
If engineer 2 can not continuously adjust his pumps mixing well water with pool water, only full on or full off, can he still stabilise his temperature?
So now we go to our tank, and take hot water as enriched CO2 water, cold water representing low CO2. The icy mountains and cooling of the pool  represent CO2 outgassing. This is hopefully a slightly different perspective to clarify the control and stabilisation process.

Now back to your summary which I find very helpful. To understand what the dream machine does:


Yugang said:


> The function of this system would be to blow a flow of water enriched with a targeted ppm CO2 (stabilised, not alternating) into the tank:



And as far as the user benefits are concerned:


Yugang said:


> A very simple procedure for user to manage a reliable CO2 injection, with a user friendly system concept
> User no longer concerned with regulator or counting bubbles. Instabilities of regulator are mitigated by feedback from pH probe and control system
> A stable, not alternating, flow of CO2 enriched water
> Fast ramp up before lights on, inherent to the systems control concept



As discussed it is a indeed reality that pH probes are proxy, and when not managed well things could go wrong. Yet reputable brands have pH/CO2 controllers already in the market, and I know from experience that the theoretical concerns / fears are in real life not such a big issue. The controllers currently in the market are very much like engineer 1 in the swimming pool analogon, that is why after several years I stopped using mine and preferred a very stable regulator and bubbles per second.

As a last user benefit, I'd hope we can imagine this as an integrated system concept with a canister, as opposed to several components (like imperfect diffusors) that need to be orchestrated by the user to work in good harmony.



KirstyF said:


> If I might also add, from a non-biased position, I do feel maybe it is somewhat unfair to assume that anyone on the forum has an agenda. They may agree or disagree and everyone is influenced by their areas of knowledge, experience and expertise, including yourself of course, but its entirely possible that they may just consider your proposition to be flawed and, right or wrong, that opinion should not IMO bring a persons integrity into question.


I take your point and do not at all feel happy with the discussion. To clarify my approach to it - I feel if someone comes out with a direct business interest, this should be transparent and the discussion will then naturally not be a pure hobby / technical discussion but inevitable involve a business aganda. As I said several times in previous postings I really like the many contributions I have seen from @arcturus over the past year, I also respect he is defending a business and I understand that many with a business interest do that from the perspective of being a hobbyist first. I hope one day he'll forgive me.


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## arcturus (16 Feb 2022)

Yugang said:


> I take your point and do not at all feel happy with the discussion. To clarify my approach to it - I feel if someone comes out with a direct business interest, this should be transparent and the discussion will then naturally not be a pure hobby / technical discussion but inevitable involve a business aganda. As I said several times in previous postings I really like the many contributions I have seen from @arcturus over the past year, I also respect he is defending a business and I understand that many with a business interest do that from the perspective of being a hobbyist first. I hope one day he'll forgive me.


With all due respect, why do you insist making these unfounded insinuations? What business are you suggesting that I represent? Can you provide a single example of a question or remark I addressed to you that is not directly related to the potential limitations of the approach you are suggesting? I think you are being unable to openly discuss an idea from a technical or scientific perspective without taking criticism too personally.

You are free to keep the discussion you started superficial and empty if you want to, but you should take a step back, read everything you have written about your "system", and maybe conclude that you have done nothing to sustain your arguments. Your idea (which is not new) is an interesting one. The challenge is how to actually overcome at least the known limitations. Just as an example, you claim one of the particular features of your system is to _"...blow a flow of water enriched with a targeted ppm CO2 (stabilised, not alternating) into the tank";  _it happens that providing a stable, non alternating flow of CO2 is exactly what a CO2 regulator and needle valve are designed to do. Also note that you have written half page reply to @KirstyF and sidestepped all the questions that were asked. I would really enjoy to discuss on how to overcome some of the challenges in measuring and controlling CO2 in an aquarium, but this is not the way to do it. Cheers!


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