# Controlling CO2 levels efficiency



## Zeus. (23 Oct 2016)

Hi all

I'm new not even got my tank yet (but we will skip that bit) been reading a lot.

So

We are after the CO2 level getting to the ideal level fast then staying there without becoming toxic to the inhabitants off the tank but high enough for optimum plant growth, but we end up with a bell curve OFC

so we are after a Table top not a bell curve ideally





( sorry just a quick job)

So ignore the cost for a moment. and just have two soleniods, needle valves, diffusers etc and just have one soleniod switch off once the "Just right" CO2 level is reach.

ovbiously you would need to play with the BBS until you hit the sweat spot

posted elsewhere thought a bit, slept on it and-

If folks are not doing it why not.

heres my take on it.

the CO2 gets into the water at a constant rate the diffusser as far as I'm aware its on or off, yes their is the pH controller method but that has issues with its use. but the C02 injection method is on or off we don't have a throttle on it the controller just switches it on and off.

My analogy

Our CO2 level is a plane on the ground,with limited fuel. we have mountain to over (we wont the CO2 at optimal level fast for obvious reasons) the engines can be on or off no throttle control. We have two engines. we can set the engine thrust (BBS) on the ground. we need 50% thrust (4 BBS) on one engine to cruise at 10,oo0 feet ( 25-30 ppm CO2) to to take off and clear the mountain we need both engines on at 50% (8 BBS combined). So we take off both engines ON reach cruising altitude switch ONE OFF. get close to our destination. switch other engine off. (or plane runs out of fuel in analogy). this would give us the ability to fly making a TABLE TOP flight giving max range (Fine control)

your thoughts and feedback welcome

Zeus


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## ian_m (23 Oct 2016)

We don't end up with a bell curve but a table top curve. You are forgetting that CO2 is always lost via surface agitation and loss rate is proportional to amount of agitation and CO2 level in the water.

So you start injecting CO2 and level rises but so does the amount lost at the surface. Eventually the loss rate matches the injection rate and CO2 stays level for the whole lighting period.

All done using one timer and one single solenoid and patience in setting it up.


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## foxfish (23 Oct 2016)

Looks like you are having fun working all your theories out 
Thing is, for me at least, I  switch my gas on two hours prior to lights and that gives me a one point Ph drop, the PH then remains stable for the next five  hours and then slowly returns to where it was.
I feel this slow build up is not to shocking for my tank inmates but equally it is simple and effective.
I am all up for experimenting though, as long as it does not harm my fish.


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## Zeus. (23 Oct 2016)

ian_m said:


> You are forgetting that CO2 is always lost via surface agitation and loss rate is proportional to amount of agitation and CO2 level in the water.
> 
> So you start injecting CO2 and level rises but so does the amount lost at the surface



not forgetting the idea is just just at its _Alpha_ stage didnt wont to start with a thread too long, some just read a bit then move on.

 It works so why change it. Triumph did that with there 750 Bonneville for years, great for spares. But.... 

but im jumping in at the very deep end with a 500l tank ( wont go there also )

So looking at an inline duffusser its rated up to 500l so the the duffusser its going to be at its limit trying to get the CO2 levels to an optimal level, as will be losing CO2 as soon as it get in tank - equilibrium with the external enviroment etc etc.So it will take longer.

So using two soleniods etc will get there faster hit optimium level for CO2 then switch one off. then one maintains the optimum level.



foxfish said:


> I feel this slow build up is not to shocking for my tank inmates but equally it is simple and effective.



Yes good point but its the CO2 levels that drive respiration ( a take it as read for fish its the same as humans since we evolved from fish millions of years ago) the water isnt o2 deficient. the fish gupp not for O2 but to get rid off CO2 respiratory alkalosis
( although the pH change might effect the max percentage O2 saturation just like temp does, but irreverent its the CO2 levels thats gets the fish) same as in appollo 13 it was the rising CO2 levels that treated the astronauts not the lack of O2, have they made a CO2 scrubber in space.
its not like jumping in a cold pool of water, just get in it twice as fast thats all.


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## doylecolmdoyle (23 Oct 2016)

Personally i have been running 24/7 co2 on my tanks with great results, very little algae and great growth... everything seems very stable. 

Both my high-tech tanks are small 12/14g so a slow rate of 1 bubble very 2 seconds 24/7 keeps my co2 ppm at about 25 - 30 at all times and when i compare to running my co2 systems on timers I am using about the same amount of co2 as I needed a much higher bubble rate when running on a timer.


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## Zeus. (23 Oct 2016)

doylecolmdoyle said:


> Personally i have been running 24/7 co2 on my tanks with great results, very little algae and great growth... everything seems very stable.
> 
> Both my high-tech tanks are small 12/14g so a slow rate of 1 bubble very 2 seconds 24/7 keeps my co2 ppm at about 25 - 30 at all times and when i compare to running my co2 systems on timers I am using about the same amount of co2 as I needed a much higher bubble rate when running on a timer.



Yes ( me the noob is going to say), sounds like your uptake by the water is slow hence to maintain CO2 levels, so your just running it 24/7 so you dont have that initail 'mountain' to climb. ( whats the CO2 level before lights come on?).
------

What I'm thinking is how to overcome that initial mountain climb first thing. If one diffusers takes two hour to reach optimal level two with same input (BBS) would do it in less than half the time in theory due to less time for loss to the atmosphere. So less waste. more efficient


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## ian_m (23 Oct 2016)

Zeus. said:


> So looking at an inline duffusser its rated up to 500l so the the duffusser its going to be at its limit trying to get the CO2 levels to an optimal level, as will be losing CO2 as soon as it get in tank - equilibrium with the external enviroment etc etc.So it will take longer.


For bigger tanks you will not be able to get decent CO2 distribution flow optimal levels using just one filter/spray bar/diffuser regardless of the CO2 levels you inject. Most people on bigger tanks end up having to use two spray bars, two filters and two diffusers in order to get optimal CO2.  See picture below.






You could of course try using CO2 venturi injection, which has been done on very large planted tanks. But is a custom piece of gear and needs very large flow rates for it to work. There is something to consider that's not been done on smaller bigger (500l) tanks.



Zeus. said:


> Yes good point but its the CO2 levels that drive respiration


Not convinced this is true for fish, as some people manage monsterous CO2 levels, even as high as 50-80ppm but have O2 injection and fish are fine.

Here is my attempt at significantly higher than 30ppm. Whoops. Fish totally unaffected.


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## Zeus. (23 Oct 2016)

ian_m said:


> input above



thanks for the input  it all helps

Planning (got some, still to finalise everything) on having Two fluval FX6 ( output 2000l/h with media, got one working on bog wood in bin, with carbon), one with Inline diffuser in INTAKE ( have read up on it ) and also and independent loop on Eheim 3000+ for two external 300Watt heaters.

Thinking of having the 'Thrust' inline diffuser on this independent loop, should get the CO2 levels to optimal levels pretty quick IMO


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## ian_m (23 Oct 2016)

How have you coped with the 25mm pipe size of FX6 and 16mm of typical diffusers.


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## Zeus. (23 Oct 2016)

took it to the Barr team


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## Zeus. (23 Oct 2016)

ian_m said:


> How have you coped with the 25mm pipe size of FX6 and 16mm of typical diffusers.



havn't yet in practice, but have checked out the flow rates for the diameters off the pipes and paln the split the STD 25mm int daimeter pipe with 'Y' fitting to 16mm pipe then back to 25mm again. Well the maths work out flow resistance should be minimal


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## ian_m (23 Oct 2016)

Zeus. said:


> havn't yet in practice, but have checked out the flow rates for the diameters off the pipes and paln the split the STD 25mm int daimeter pipe with 'Y' fitting to 16mm pipe then back to 25mm again. Well the maths work out flow resistance should be minimal


Yes that's the way to do it. Might want to put a valve in the non CO2 route so you can force the flow through the diffuser side if required. Also remember to stainless jubilee clip all joints.

Actually what some people do is leave straight route bypassing the diffuser 25mm with valve and have the CO2 route 16mm as gives more control of flow rate through the diffuser.


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## Zeus. (23 Oct 2016)

ian_m said:


> Yes that's the way to do it. Might want to put a valve in the non CO2 route so you can force the flow through the diffuser side if required. Also remember to stainless jubilee clip all joints.
> 
> Actually what some people do is leave straight route bypassing the diffuser 25mm with valve and have the CO2 route 16mm as gives more control of flow rate through the diffuser.



Opps My bad plan on Inline Atomizer CO2 Diffuser  best get editting 

so flow would be even longer time in pipe slightly better


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## Zeus. (23 Oct 2016)

The idea is to basically have one of the filters as a Cerges reactor in a way - slow the bubbles down, ups and downs of flow, lots of media  to bump into more time to get into water less bubbles in tank. As for there mass of bubbles from the indepentent loop in the morning thrust stage, well be like Xmas


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## ian_m (23 Oct 2016)

Before you connect your diffuser inlet you might want to consider what CO2 can do to rubber seals in the filter.

http://www.ukaps.org/forum/threads/bubble-counter-seal.43147/



Zeus. said:


> havn't yet in practice, but have checked out the flow rates for the diameters off the pipes and paln the split the STD 25mm int daimeter pipe with 'Y' fitting to 16mm pipe then back to 25mm again. Well the maths work out flow resistance should be minimal


Not quite.

16mm tubing is 200mm2 and 25mm is near 500mm2, which explains why people put the diffuser on 16mm bypass of 25mm straight through tube (with valve).

See post below on how to hook up 16mm diffuser to 25mm pipe.
http://www.ukaps.org/forum/threads/fluval-fx6-with-16-22m-hose.42310/#post-455324


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## Zeus. (23 Oct 2016)

CO2 can do to rubber seals in the filter - found thread somwhere else bit back folk using it for few years np if it does move CO2 input to outlet of filter and replace seal/impeller.

Pipe size, sorry my mistake wasn't clear on plans,plan going to spit Y the pipe to two 16mm pipes.diffuser on one side, bypass on other. (Used the Bernoulli equation did the maths-np )- then back to 25mm


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## Zeus. (23 Oct 2016)

Well I think I may have come up with an original Idea/modification/ technique
So

Legal disclaimer- Zeus and UKAPS or any other website takes no responsibility or liability, that if you or any third party you tell about this technique. Using CO2 can be dangerous to your livestock and humans leading to respiratory alkalosis and/or death. Any use of this technique is done at your own risk. However feel free to try use the technique at your own risk. I/ we welcome any feed back.

Zeus

May be premature  But If any one else can make a valid claim to the idea/modification/ technique pls let me know before I name it.


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## doylecolmdoyle (23 Oct 2016)

Zeus. said:


> Yes ( me the noob is going to say), sounds like your uptake by the water is slow hence to maintain CO2 levels, so your just running it 24/7 so you dont have that initail 'mountain' to climb. ( whats the CO2 level before lights come on?).
> ------
> 
> What I'm thinking is how to overcome that initial mountain climb first thing. If one diffusers takes two hour to reach optimal level two with same input (BBS) would do it in less than half the time in theory due to less time for loss to the atmosphere. So less waste. more efficient




I am not sure what you mean by the "sounds like your uptake by the water is slow" the only time that more co2 needs to be dissolved into the water if I am running 24/7 co2 is after a water change otherwise my level of co2 is 25-30ppm 24/7. Lights come on and my plants are pearling 15 minutes later. I also run a surface skimmer which helps control co2 and create a nice amount of surface agitation.


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## Zeus. (23 Oct 2016)

doylecolmdoyle said:


> I am not sure what you mean by the "sounds like your uptake by the water is slow" the only time that more co2 needs to be dissolved into the water if I am running 24/7 co2 is after a water change otherwise my level of co2 is 25-30ppm 24/7. Lights come on and my plants are pearling 15 minutes later. I also run a surface skimmer which helps control co2 and create a nice amount of surface agitation.



Firstly I have zero experience, What I said is just theory. What you works for you thats great so pls do not change anything on what I say.  I said slow as if your night period is longer than day period you should be using less CO2 but said said about the same, which sound like less CO2 was diffusing into water as it was saturated at near to the diffusser therefore more bubble escaping to surface - hence slow - at lower BBS there is a higher duffusion gradient so fast uptake all any CO2. But at a higher BBS once the initail CO2 (2 BBS) is taken up the extra CO2 (2 BBS) has to fight against a higher diffusion gradient. as the waters affinity for CO2 is limited. Hope that makes sense



doylecolmdoyle said:


> Personally i have been running 24/7 co2 on my tanks with great results, very little algae and great growth... everything seems very stable.
> 
> Both my high-tech tanks are small 12/14g so a slow rate of 1 bubble very 2 seconds 24/7 keeps my co2 ppm at about 25 - 30 at all times and when i compare to running my co2 systems on timers I am using about the same amount of co2 as I needed a much higher bubble rate when running on a timer.



My take/theroy would be.

Lights on say 8Hrs so for 14hrs of night your CO2 input plus plants CO2 would yeild a higher CO2 ppm but not dangerous as everything is fine. But there could be times that the CO2 level is getting close to critical for fish. Lights come on and plants very happy as plenty of CO2 and the CO2 ppm of tank must drop as the plants are using it.

You said to get the same level of CO2 with it on in day only you had to run it at a higher level (BBS) to get it to your chosen level. Which should use less CO2 if you was hitting the same CO2 ppm on both methods. But with the 24/7 method you run a higher chance of respiratory alkalosis for you fish.

surface skimmer = increased water agitation = greater CO2 loss - Pls dont turn it off if your 24/7 with CO2 as a clean clear surface helps CO2 escape from water too.

What I am proposing is if we was to take your tank for example (pls don't do this on my account your risk OFC)

one diffusser/reactor (what ever your using) you know the rate the maintain isdeal CO2 levels for tank 1-2BBS that would come on say 30mins before light period. at the same time a second diffusser/reactor would come on at the same time say 3BBS you would reach you ideal CO2 ppm faster then the second one switches off. fish happy at night plants happy in day uses Less CO2, but more initail outlay on hardware


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## Staticrzr (24 Oct 2016)

man, is it just me because I'm not British? I can't understand a word Zeus says. I read some of his posts two times and still nothing is making any sence.


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## ian_m (24 Oct 2016)

I do feel you are overcomplicating things, especially for so little anticipated gain (sorry what was the advantage again?), compared to what everyone else does, as well exposing yourself to killing all your fish if your boost diffuser system jams on.

I have had numerous timer failures in my years, most common is complete timer death, no display nothing. Does lead to algae obviously if CO2 timer fails. But second most common failure I have encountered is stopping of timer with output in what ever state is was on. One time I emptied 1 litre of EI macro solution into my tank giving 300ppm nitrate for a couple of days, no issues as nitrate is generally not toxic at these levels, contrary to popular incorrect knowledge. Second time it was a liquid carbon dump and this did kill fish and melt plants. I have much better timer control now.

If my CO2 failed to on, due to timer failure, then I would just end up with 30ppm CO2 24/7. Fine. Just a waste of CO2 during non light hours.

Couple of other issues I have been pondering on are:

- How will you know when to stop your boost diffuser (10 minutes ? 25 minutes ?) as, if it works, you will have a fairly limited time window, 5 minutes maybe, before you will start gassing your fish.
- CO2 is not very soluble in water and I suspect you will not be able to get enough CO2 to dissolve from a conventional diffuser into the water in order to raise the CO2 of 500litres in 30minutes as you hope for.

Sorry not convinced your idea gains anything helpful other than yet another way to kill your fish more easily.


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## Zeus. (25 Oct 2016)

Staticrzr said:


> man, is it just me because I'm not British? I can't understand a word Zeus says. I read some of his posts two times and still nothing is making any sence.


Sorry Dyslexic m8 

Ok took some time with this so hopefully makes sense

(Made some progress with graphs I had planned, Henery’s law etc, etc, then slept on it and subconscious mind was busy all night!! And took it to the next level )

Long post warning!!! Sorry

In Toms classic Puddle of mud there was no flow (at first) and the tank thrived – Low tech tank OFC. High tech tanks users tend to aim for x10+ turnover as that’s what works well OFC.

Its all about the speeding up the mixing of nutrients when we play ‘God’ in the high tech tank because of the effect of Mass Diffusivity of Mass in water in being very very very slow

-------------------------------------------------------------------

Comparison of diffusion of CO2 in Air and water for example-

In this comparison we assume the CO2 travels in a straight line ( which OFC it does not. There’s random movement and a concentration gradient, but to make it simple we will ignore that)

Carbon dioxide in air has a diffusion coefficient of 16 mm2/s
so for a tank 1.6m long in air would take 100secs to reach other side off tank

But
Carbon dioxide in water its diffusion coefficient is 0.0016 mm2/s
so for 1.6m tank would take 1,000, 000 seconds or 11.5 days

That’s 10,000 times slower so in a high tech tank we need good turnover, (x10) to mix the CO2 and nutrients when we play ‘God’ over our ecosystem

-----------------------------------------------------------

So what I’m postulating is that this x10 turnover may not be needed all the time! and that this turnover is decreasing efficiency when on 24/7, as the CO2 is being lost faster at the surface, we may only need the x10 turnover for times when we want to drastically change the concentrations and mix anything, eg When we want to change the Waters Carbon Dioxides Concentration ([CO2]aqu)  for plant growth before the lights come on.

So ‘say’ you have turnover rate of x5, so adequate water surface movement to get enough gaseous exchange in at night and maintain equilibrium in the tank ie Balanced between the atmospheric air, water column, Substrate(High CEC)and keep at right temp.

But in High tech tank we want to dramatically change the [CO2]aqu and Mix the ferts.,( we can not change the laws of physics!) so with mass diffusivity being so slow in aqueous media we need a higher turnover (x10) to enable us to reach the  new desired  levels [CO2]aqu relatively quickly. But once at the desired level and equilibrium is reached the x10 turnover will be helping the [CO2]aqu fall. So once we have reached the ideal [CO2] turn the turnover down to x5!( get the slow mass diffusivity to work to our advantage)  As after all we have to do is to maintain the [CO2]aqu to take care of surface loss and plant uptake. During this X10 turnover period would (IMO) be the ideal time to have a higher rate(BBS) of CO2 input (have the Ferts auto dosing at same time too) this period can last for say one hour. Then reduce turnover x5 with just enough CO2 (BBS) to maintain those ideal levels. This lower flow rate won’t need as much surface ripple either as all we want is a slower flow, so water return for this could possibly be lower, therefore reducing CO2 loss even more.

Run the x10 turnover for one hour when lights go off too.(no CO2 OFC). These two one hour periods with X10 (or more!) turnover rates may be even enough to keep on top of the detritus build up as good as 24/7 x10

There we have it, dawn of the ‘Eco High Tech Tank’. Yes more initial setup costs timers, pumps etc.

But less CO2 usage, less power consumption with running lower turnover rates for most of time, less heat loss from tank, less evaporation from tank……

Two workout periods for fish. Just like nature in way in estuaries, rivers, rain forests, windy periods The water flow rate changes and isn’t constant

For smaller tanks the effort and cost just wonted be worth it but for the bigger tanks with multiple canisters,  pumps, power heads CO2 diffusers/atomisers etc the relatively small cost of a few timers might make a difference to the running cost.

Will it work – dunno, what settings for turnovers times –dunno Its just an idea of a Noob

But can’t see why it wouldn’t work as well  

Thanks for reading – Kudos due ( hope the grammer spelking was Ok)

I welcome any feed back

Zeus


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## Zeus. (25 Oct 2016)

ian_m said:


> I do feel you are overcomplicating things



yes may be but same was said of hybrid cars some time ago but still there are here, just running with the idea thats all



ian_m said:


> as well exposing yourself to killing all your fish if your boost diffuser system jams on.
> 
> I have had numerous timer failures in my years, most common is complete timer death, no display nothing. Does lead to algae obviously if CO2 timer fails. But second most common failure I have encountered is stopping of timer with output in what ever state is was on. One time I emptied 1 litre of EI macro solution into my tank giving 300ppm nitrate for a couple of days, no issues as nitrate is generally not toxic at these levels, contrary to popular incorrect knowledge. Second time it was a liquid carbon dump and this did kill fish and melt plants. I have much better timer control now.



Timer issues - yes good point  KISS principle all over. was that the old analogue macanical timers or the new digital times or both ?



ian_m said:


> - How will you know when to stop your boost diffuser (10 minutes ? 25 minutes ?) as, if it works, you will have a fairly limited time window, 5 minutes maybe, before you will start gassing your fish.
> - CO2 is not very soluble in water and I suspect you will not be able to get enough CO2 to dissolve from a conventional diffuser into the water in order to raise the CO2 of 500litres in 30minutes as you hope for.



Trail and error or pH controler maybe



ian_m said:


> Sorry not convinced your idea gains anything helpful other than yet another way to kill your fish more easily.



Agree 100%, just running with the idea. your post highlight the failings of the idea which is what I am after then I can decide if to try it or not.
 After all what did folks think of Takashi Amano when he fist added baking soda in his tank and overcompicated things, but High tank tanks are still here not saying this idea is anything like as profound as his in any way. but it has it points - maybe!!!


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## Zeus. (26 Oct 2016)

OK - would you buy or think buying the latest

ADA Eco-Utratech- Ecosystem Complete

Product features – small compact unit with twelve independent/configurable (via software) power outputs240v/110v/24v/12,v, pH sensor, temp sensor, flow sensor, Precision variable( by software) CO2 valve , WiFi,LAN, HDMI, VGA,DVI,USB, software with Windows/Mac compatibly, allows you monitor/adjust/program Temp,CO2 input, CO2 ppm, flow rate though pump, Pumps RPM pump, ampage usage by pump/canister, control program for lights adjust volt/amps plus auto dosing control/tank topup control also. Then add smart app on your phone with full control/monitoring/alarms etc.

Would you buy it, think would help make Aquascaping easier/better ?

Basically give 'God' like control over the tank. If the answer is NO I’m wasting my time.


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## Zeus. (30 Oct 2016)

The link for the ADA Eco-Utratech- Ecosystem Complete isn’t possible is not on the web or the dark web, I would need a spinal interface link me up to web and the addresses would end something Like …zeus/noob/backoff mind/wizbangideas/offhisrocker/adaecoultratechecoesystemcomplete thnk you get my drift

But if there was one and at £50 mine would be ordered. So I have been searching/reading on remote management systems with smart phone apps etc. There is a lot out there. Some very expensive industrial system very cool but cost too much. Then there the reasonably priced ones available. Eg LightwaveRF and Energenie.

I was thinking I might be able to vary the water pumps speed by altering the current. So emailed the company’s in question and got the answer NO. Wasn’t put off with that reply took a dimmer light switch rigged up a plug and socket and gave it a try. They were right, decrease the available current to the pump it slows a little then it stops. So the idea of controlling water flow rates with dimmer switch is out the window. The pump is on or off, yes can adjust the values but can’t do it remotely or on a schedule without a remote adjustable value, so dropped that idea.

Wasn’t after light dimming as already have Kessil controller for lights

Most off the Remote units use a WiFI or Lan connection to communicate via smart app with the main control unit. Ok no problem with that as long as the schedules is being run from the control unit. After all remote access is just a bonus. It’s the RF communication between the control unit and the sockets, it can be hit and miss at times. We need something reliable 100%.

So ordered myself

*Energenie LAN Power Management System £65* (great specs) with smart app control.

Which will allow me to play with the timings easy, 16 a day per socket (4off) and I can have a play with the “Zeus booster” idea that’s will cost me £70 extra for extra CO2 equipment.

If the “Zeus boost” idea fails ( which it might well do ) I ready to add another tank CO2 wise


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## ian_m (30 Oct 2016)

Zeus. said:


> *Energenie LAN Power Management System £65* (great specs) with smart app control.


I looked into one of these, but after seeing all the fish killing and greenhouse flooding issues people had (see Amazon reviews), I steered well clear. Mainly the review issues of "really good when it works" rings alarm bells. Also rather large (40cm) thus will have issues fitting neatly on a lot of aquarium cabinets depth wise.

I finally after much searching, built a 12 output industrial quality programmable logic controller (PLC) to control my tank. (see DIY projects list) and has obviously worked 100% since fitting. Even changed the clock correctly today as well.

For your Zeus booster you really should be looking at using a PLC, normal on/off timers won't cut it. With a PLC it will be able to turn off CO2 when correct level, control multiple lights and lots of other interactive things.


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## Zeus. (30 Oct 2016)

ian_m said:


> I looked into one of these, but after seeing all the fish killing and greenhouse flooding issues people had (see Amazon reviews), I steered well clear.



Cheers 

was that the Old USB one as the new Lan one has battery backup so schudule returns to normal after power off.

can you remember the name of the thread you did with the PLC ?

found it *How to use a PLC to control your fish tank. *


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## ian_m (30 Oct 2016)

Zeus. said:


> was that the Old USB one as the new Lan one has battery backup so schudule returns to normal after power off.


Ah yes USB. Right pain in a*8e as needed to be near a PC to configure/setup.

CO2 (and temperature) control using PLC. Done.





My PLC big boy timer. The MNDB. (read thread to see meaning) is below.
http://www.ukaps.org/forum/threads/how-to-use-a-plc-to-control-your-fish-tank.42993/

I am currently working on MK II where you just set light on and off times and it times CO2, wavemaker, bright lights, fertz and air pump around the one timer setting as opposed to having loads and loads of individual timers like mine above has.


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