# Reactors - separate up or inline ?



## tubamanandy (28 Nov 2016)

My reactor is currently inline from my large Eheim external filter - although it works great, flow is severely impeded.

Do most people that havew a reactor use this arrangement or do you have a separate pump/powerhead ?


----------



## ArcticFox (10 Dec 2016)

tubamanandy said:


> My reactor is currently inline from my large Eheim external filter - although it works great, flow is severely impeded.
> 
> Do most people that have a reactor use this arrangement or do you have a separate pump/powerhead ?


I am also in this situation I have a eheim2080 and have the larger insta reactor and it has killed my flow....I am looking for a better solution for a 260ltr bow front. I also have a fluval 106 attached....but that is used for surface agitation, water polishing and purigen......using this filter would have its flow killed off and also I have it returning close to surface via a ducksbill outlet so no good for CO2..........have you had any other advice?


----------



## Ryan Thang To (11 Dec 2016)

Have you ever try co2 straight into your filter as a reactor? I been doing that way for a few years work great.

Cheers
Ryan


----------



## MrHidley (11 Dec 2016)

Ryan Thang To said:


> Have you ever try co2 straight into your filter as a reactor? I been doing that way for a few years work great.
> 
> Cheers
> Ryan



I did this for a while, but it made my filter burp all the bloody time.


----------



## foxfish (11 Dec 2016)

I think the whole 'Aquatic plant keeping world' is waiting for a simple effective external reactor to become available!


----------



## Andrew Butler (29 Dec 2016)

I'm looking into inline CO2 and are you guys saying it's not the way forward?


----------



## MrHidley (29 Dec 2016)

Andrew Butler said:


> I'm looking into inline CO2 and are you guys saying it's not the way forward?



Inline Diffusers are probably the best thing right now. Reactors are kind of old and archaic at this point.


----------



## Andrew Butler (29 Dec 2016)

ah, being a novice I assumed they were the same thing! Can you give me some pointers about which components work and don't please?!?


----------



## MrHidley (29 Dec 2016)

I use these on almost on all but one of my high tech tanks https://www.co2art.co.uk/collection...ine-co2-atomizer-diffuser-system-12-16mm-hose These often need a higher working pressure than intank diffusers but all the standard single stage regulators from co2 art create enough pressure.

The other one is only a 35L tank so I use an in tank diffuser https://www.aquasabi.com/co2/co2-diffuser/aquario-neo-co2-diffusor-u-type


----------



## Andrew Butler (29 Dec 2016)

I'm guessing co2art are a good source. Should I just go for a kit? what about sourcing CO2?


----------



## foxfish (29 Dec 2016)

The standard in line atomiser is probily the most popular way to introduce Co2 into the modern planted tank but they produce a visible fine mist within the display. 
In line reactors, dissolve the co2 before it reaches the display but zap flow rates and can have other issues like noise and size!


----------



## MrHidley (29 Dec 2016)

Andrew Butler said:


> I'm guessing co2art are a good source. Should I just go for a kit? what about sourcing CO2?


 Co2art have been superb in my experience. I've never had to source co2 because my father supplies extinguishers for a living. You can probably get one from eBay though.


----------



## JOHN STEVENSON (11 Mar 2018)

foxfish said:


> The standard in line atomiser is probily the most popular way to introduce Co2 into the modern planted tank but they produce a visible fine mist within the display.
> In line reactors, dissolve the co2 before it reaches the display but zap flow rates and can have other issues like noise and size!


Hi, i want to use an external reactor, but i need to know if i can put it above or below my external heater, im worried that the flow restriction will have a negative effect on the heater. Can you please advise.


----------



## Zeus. (11 Mar 2018)

JOHN STEVENSON said:


> Hi, i want to use an external reactor, but i need to know if i can put it above or below my external heater, im worried that the flow restriction will have a negative effect on the heater. Can you please advise.



Fit a bypass parallel with the CO2 reactor I did and it works fine More detail here


----------



## Andrew Butler (28 Mar 2018)

JOHN STEVENSON said:


> external reactor


As Zeus says you can fit a bypass but you need the space for this.
Is there a reason you don't want to opt for an atomiser? I have hard water and they just clog up too quickly for my liking meaning you have to take everything apart to clean them so ideally also need a spare - that's just my input though.
I've just received my reactors which I admit I am yet to test but I don't think they are going to effect flow from some testing I did using pipe and bends.
I have had them made specially for me as the ones available are from what I read a pile of poo and by the time you buy the parts to make one yourself you can do as I did and get one made from acrylic.
I just hope they work now!


----------



## Mark Grigg (29 Mar 2018)

tubamanandy said:


> My reactor is currently inline from my large Eheim external filter - although it works great, flow is severely impeded.
> 
> Do most people that havew a reactor use this arrangement or do you have a separate pump/powerhead ?


Can you oversize the reactor, step up from say a 12mm to a 16mm pipe, then down to 12mm again, thus the bottleneck will be enlarged?


----------



## Zeus. (29 Mar 2018)

Mark Grigg said:


> Can you oversize the reactor, step up from say a 12mm to a 16mm pipe, then down to 12mm again, thus the bottleneck will be enlarged?



Yes you can but even with oversizing you increase the Total resistance of the filter/ reactor setup and reduce the flow.



tubamanandy said:


> Do most people that havew a reactor use this arrangement or do you have a separate pump/powerhead ?



I could run mine with either the filter (FX6) or my independent line (Eheim 3000+) but choose to have the reactor post filter as it helps reduce the detritus buildup in the reactor and inline atomiser. When I clean the pipework post Eheim 3000+ there is plenty of detritus but post FX6 is no where near as bad so a no brainier IMO


----------



## wolfewill (30 Mar 2018)

I draw water from my main filter inflow lines with a 'T' or a 'Y' splitter to a smaller polishing filter which then feeds to an inline diffuser followed by a reactor with a separate line back to the tank. The extra head does reduce the flow considerably for this line, but the main filter is used only as a bio filter with coarse filtration only, so this doesn't impact its flow rate at all. So the flow problem is eliminated, the water is polished with a smaller, easier to clean filter packed with fine filter floss, and so keeps most debris out of the diffuser and reactor. The issue is getting the right size of reactor and filter.


----------



## Danielm (30 Mar 2018)

Apologies for slightly hijacking the post but when you talk about inline, does this simply mean adding CO2 somewhere along the return line from an external filter, via some type of T connector?


----------



## Zeus. (30 Mar 2018)

Danielm said:


> Apologies for slightly hijacking the post but when you talk about inline, does this simply mean adding CO2 somewhere along the return line from an external filter, via some type of T connector?



Yes directly inline  which is how most folk do it, or via a bypass as I have done it. On the return feed from the filter is correct - gets the hardware out of the tank


----------



## Danielm (30 Mar 2018)

Zeus. said:


> Yes directly inline  which is how most folk do it, or via a bypass as I have done it. On the return feed from the filter is correct - gets the hardware out of the tank



Thanks Zeus - if I am running a sump, could I simply put a a diffuser in the return pump chamber - for various reasons I don’t want to T into/off the return pump.


----------



## foxfish (30 Mar 2018)

You can just stick your co2 line straight into the return pump, you will get a mist but it is a tried and tested low maintenance method.


----------



## Zeus. (30 Mar 2018)

Foxy beat me too it 

Yes you can, running a sump uses more CO2 for a given tank [CO2] , as the CO2 gases off via the surface of the sump, bigger the sump the bigger the loss. Having a lid on the sump reduces the losses and a seal sump is called a 'canister' which loses less OFC


----------



## Danielm (30 Mar 2018)

Thanks gents


----------



## wolfewill (30 Mar 2018)

Danielm said:


> Apologies for slightly hijacking the post but when you talk about inline, does this simply mean adding CO2 somewhere along the return line from an external filter, via some type of T connector?


No. See this for an example of an inline diffuser:
https://www.co2supermarket.co.uk/up-inline-atomizer-co2-diffuser-12-16-p188.html


----------



## Onoma1 (17 Aug 2018)

I have just taken off my in-line reactor (pic below) as both seemed to reduce the flow (considerably) and was quite noisy. I understand that they do reduce the flow, however, wondered if anyone could suggest an alternative brand?


----------



## foxfish (17 Aug 2018)

There is a  shortfall of reactors on the market, many of use have been waiting years for a large manufacture to come up with something that works well at a reasonable price. 
The model you have would of  been fantastic if it was twice the size and did not have those stupid impellers!   
You can dedicate an external filter, this is quite a popular method, not ideal but possibly a better bet than what you were using but as you don’t mention any details about you tank it is differcult to recommend much.


----------



## becks (17 Aug 2018)

I’m going to diy one with a 10” RO canister with 1” fittings, there’s also a screw for bleeding  air from the unit that I will replace with a nipple for CO2 injection


----------



## Iain Sutherland (17 Aug 2018)

The best reactor out there is the aqua medic 1000, with the balls removed the flow isn't impeded too much and still works a treat.

Sent from my SM-G950F using Tapatalk


----------



## becks (19 Aug 2018)

has anyone calculated the flow loss from a sera reactor?


----------



## Zeus. (19 Aug 2018)

Iain Sutherland said:


> The best reactor out there is the aqua medic 1000, with the balls removed the flow isn't impeded too much and still works a treat.



Well I just had a look at the specs for the aqua medic 1000 and with its 1/2inch inlet gives it about the same bottleneck as the APS EF2




APS has an elbow which doesnt help flow, but what the APS EF2 lacks in length it makes up for in width. But APS EF2 isnt translucent 

APS EF2 £20


----------



## becks (19 Aug 2018)

EF External Filter Booster Supplimentary Canister 1.2L is clear? could you not use that? that make a slightly bigger one too


----------



## Zeus. (19 Aug 2018)

becks said:


> EF External Filter Booster Supplimentary Canister 1.2L is clear? could you not use that? that make a slightly bigger one too



It's clear in the advert but they only do the white opaque canister base, well that's what APS informed me when I contacted them about getting a clear canister.


----------



## becks (20 Aug 2018)

has anyone tried putting the co2 inlet into return pipe after the filter? Did it dissolve ok by the time it reached the outlet?


----------



## Zeus. (20 Aug 2018)

becks said:


> has anyone tried putting the co2 inlet into return pipe after the filter? Did it dissolve ok by the time it reached the outlet?



I have fitted an online atomiser to the return of the filter and the bubbles failed to dissolve so if bubbles with a large surface area to volume ratio fail to dissolve a large bubble with a low surface area to volume ratio has no chance of dissolving before being released to the atmosphere. If a CO2 reactor is fitted then that's another story OFC


----------



## becks (20 Aug 2018)

Zeus. said:


> I have fitted an online atomiser to the return of the filter and the bubbles failed to dissolve so if bubbles with a large surface area to volume ratio fail to dissolve a large bubble with a low surface area to volume ratio has no chance of dissolving before being released to the atmosphere. If a CO2 reactor is fitted then that's another story OFC



I’m just thinking of ways to limit flow reduction, I guess I need to start experimenting  I might make a diy reactor copying the design of the aquamedic one, as that appears to be the most flow friendly reactor I’ve seen.


----------



## tiger15 (21 Aug 2018)

Mine is neither inline or separate, as I don’t run any canister filter.  I use Tunze co2 reactor which operates independently with its own power head.  I’m very pleased with it as it is trouble free, quiet, and delivers CO2 in 50/50 dissolved and misty phase.   

https://www.google.com/search?q=tun...8&hl=en-us&client=safari#imgrc=AmvIdoXR8xC93M:


----------



## foxfish (21 Aug 2018)

I spent many a day experimenting with DIY reactors, some worked very well, some worked for me but not for others who tried the same designs!
There are so many variables that can effect performance, size on tank, amount of flow, amount of C02, power of pump etc....
However the basic principle is ..... to maintain a contact time between the gas bubbles and the tank water that is long enough to completely dissolve the C02.

In theory, a simple  tube would do the job but it would need to be very long.
If you can spin the water inside the tube then the travel time increases, if you can form a vortex then the contact time will increase tenfold over and over again!

Another way, would be to restrict the C02 path by adding bio balls or similar, a further improvement would be to place the C02 against the flow of water.
This is the most popular method that commercial reactors use but, that method will obviously reduce flow.

The main problem with a DIY vortex revolves around finding a suitable vessel and finding a way to spin the water.
The inlet and outlet would ideally enter the vessel at an extream tangent and that is not easy t to DIY.

What we need is a large company to produce a suitablely sized, clear, vortex reactor that won’t reduce flow to much.

I posted this thread a few years back now https://www.ukaps.org/forum/threads/high-flow-diy-reactor-now-with-video.23337/ the reactor still works extreamly well although it is opaque now.
However the vessel is not a common size and the new under sink water filters are quite a bit smaller.


----------



## foxfish (21 Aug 2018)

I spent many a day experimenting with DIY reactors, some worked very well, some worked for me but not for others who tried the same designs!
There are so many variables that can effect performance, size on tank, amount of flow, amount of C02, power of pump etc....
However the basic principle is ..... to maintain a contact time between the gas bubbles and the tank water that is long enough to completely dissolve the C02.

In theory, a simple  tube would do the job but it would need to be very long.
If you can spin the water inside the tube then the travel time increases, if you can form a vortex then the contact time will increase tenfold over and over again!

Another way, would be to restrict the C02 path by adding bio balls or similar, a further improvement would be to place the C02 against the flow of water.
This is the most popular method that commercial reactors use but, that method will obviously reduce flow.

The main problem with a DIY vortex revolves around finding a suitable vessel and finding a way to spin the water.
The inlet and outlet would ideally enter the vessel at an extream tangent and that is not east to DIY.

What we need is a large company to produce a suitablely sized, clear, vortex reactor that won’t reduce flow to much.

I posted this thread a few years back now https://www.ukaps.org/forum/threads/high-flow-diy-reactor-now-with-video.23337/ the reactor still works extreamly well although it is opaque now.
However the vessel is not a common size and the new under sink water filters are quite a bit smaller.
Here is the video but I can’t seem to get a live embedded link?
https://m.youtube.com/watch?feature=plcp&v=vgt3COKNIqg


----------



## zozo (21 Aug 2018)

I'm not into CO² anymore at the moment.. And i actualy do not know if i ever will again.. I'm a lazy bum and got tired trimming plants and cleaning all the alage i grew with it. I seem to grow less algae with long term low tech aqauriums. 

Anyway, the few years i played with it i did some reading on alternative ways to add it or to improve the dissolving.. And found quite some data on experiments where they found out that a venturi works the best even in low flow system a venturi significantly outperformed a regular diffuser.

Never got around to build me a DIY construction with a venturi behind the diffuser, so far it's still a theory about how it would performe in a tubed aqaurium filter system and a small tank. The experimental data i found on it was all about ponds and bigger setups than relatively low flow concept will exceed aqaurium flow quite a bit. And i know the Big Amano setup in portugal also uses a venturi system to add co².  In swimming pool systems a simular venturi device is used to sufficiently add co² to lower the pH.

The working principle is rather straight foreward and it is the pressure difference in the system making co² dissolve beter.. The co² is added (partialy diffused) in front of the venturi / choke tube.. There will be a pressure build up in front of the venturi, the water is choked and speeds up to get through the narrow part. Behind the venturi there will be a pressure release again and a vortex.. Both the vortex scaters the co² bubbles into smaller particles and this sudden presure difference (expansion) behind this choke point, the co2 molecules get sucked into the water. It's actualy the very same priciple as the venturies used at powerheads outlet to create a mist of air bubbles.

I guess the venturi concept in the aqaurium hobby yet didn't got any foothold because of the rather low pressure pumps build in the standard filters. Most standard pumps used rarely exceed 2 metre head, than there will be signifcant unwanted flow loss working counter productive again regarding co2 distribution in the tank itself. And loss of filtering capacity which is rather important in high energy setups. But as said, never experimented with this concept personaly. If i ever go CO² again i definitively will explore it..  But i guess making it work requires some oversizing of pump and filter capacity.


----------



## foxfish (21 Aug 2018)

It would work but you will be producing a mist and as you point out Venturi work by restricting flow.
Perhaps the best examples are marine Venturi skimmers.


----------



## zozo (21 Aug 2018)

foxfish said:


> It would work but you will be producing a mist



I'm not sure i fully agree with this.. Because the very same principle is already in use.. As said, that big amano scape in portugal uses a venturi system to add co2.. And in swimming pools it is the most durable technique available any other way creates more waste than effect.

Looking at such a power head with a venturi, this indeed creates a mist.. It should do that it's in size designed for it the outlet is rather emidiate behind the venturi.

Looking at the bigger systems and how they are setup looking at the diagrams. It is build inline in a shunt. I guess the longer the water travels a line behind the venturi only makes it disolve even beter.. If it was installed directly at the water outlet, than it might indeed only create a mist same as the powerheads air disperse venturies do.

And also these air venturies come in different designs, some create larger bubbles others create a fine mist.. I yet didn't get my hands on the different versions out there.. They are not easily for sale as spare part. SInce i'm not into it anymore, i'm reluctand to by me a collection of powerheads only to look at the venturi designs.. 

But i think with building in a shunt, actualy just sizing down the big boys in use for bigger systems.. It can be done.. Might need to DIY the venturi with the proper equipment.. That's also an issue for me at the moment, would need a Lathe to play, i don't have (yet)..


----------



## foxfish (21 Aug 2018)

Interesting.. I wonder how that works?
Every Venturi I have seen or built or used produces billions of micro bubbles?
Perhaps the Venturi is just a first stage followed by a reactor?
Most skimmers have a dedicated hight performance pump to compensate for the loss of flow.


----------



## zozo (21 Aug 2018)

As far as i understood the explaination it's mainly the pressure drop in the tube behind the ventiry responsible for sucking in the co² mulecules into the water. So there is a co² bubble sucked into the venturi, the vortex shreds it the pressure drop sucks it in. Along teh way through the tubing it dissolves even more before it hits the outlet..

Than my assumption placing a venturi behind a simple inline difuser can only be very beneficial regarding dissolving the microbubble even further.. 

As seen in the video, it's not realy a microbubble that is shreded, i also see some rather large bubles beeing spit out. I guess it comes down the the starting bubble size.

And it also seems to work in a rather low flow system, in the diagram it was placed in a shunt line (By pass)



 

With partialy closing the main inline valve a portion of the flow will go over the venturi and a portion of the flow will go straight on. A also assume that the flow in teh main tube should be greater. Than the diffused Co² will hit a increasing flow again coming from the shunt, again a possitive effect on further dissolving.

This is simply how it is adviced and installed by poolbuilders as the most sufficient ph nutralizer for swiming pools with the use of co² and a ph controler.. Any other way will cost you more if not to much co².. I have a hunge it is such a same swimming pool diffuser they use in lisbon..

And in mini version this should be awfully simple to DIY.. Theoreticaly.. If the pump can handle it...


----------



## zozo (21 Aug 2018)

Here is actualy the full explaination.  Maybe not where you expected it to find. And maybe something you still use every day or have used it. But even if the mediums are switched from shreding fluid into air to make a gass into shreding gass into fluid. In general the physical principle is the excact same.

Read CO² instead of Fuell and Water instead of Air..


> *How does a carburetor work?*
> Carburetors vary quite a bit in design and complexity. The simplest possible one is essentially a large vertical air pipe above the engine cylinders with a horizontal fuel pipe joined onto one side. As the air flows down the pipe, it has to pass through a narrow kink in the middle, which makes it speed up and causes its pressure to fall. This kinked section is called a *venturi*. The falling pressure of the air creates a sucking effect that draws fuel in through the fuel pipe at the side.



https://www.explainthatstuff.com/how-carburetors-work.html

It actualy is a CO² carburator in a water line..


----------



## tiger15 (22 Aug 2018)

foxfish said:


> However the basic principle is ..... to maintain a contact time between the gas bubbles and the tank water that is long enough to completely dissolve the C02.
> https://m.youtube.com/watch?feature=plcp&v=vgt3COKNIqg



The goal is not necessary to get 100% CO2 dissolved to achieve the the greatest impact.  Barr has demonstrated that plants can uptake misty CO2 that attached to leaves more efficiently than dissolved CO2.  The theory I recalled is that plants have to expend energy to convert carbonic acid back to free gas so as to uptake CO2.  Amano tanks use diffusers to create mostly CO2 mist rather than dissolved.


----------



## zozo (22 Aug 2018)

tiger15 said:


> Barr has demonstrated that plants can uptake misty CO2 that attached to leaves more efficiently than dissolved CO2



Also logicaly this would makes a lot of sense. It's a simple sum.. Given that the co2 bubble actualy attaches to a leaf. The thing i'm rather sceptic about is how did the demonstration show the difference in "What's an oxygen bubble and what is a co2 bubble?.  Since it's the stomata responsible and at the leaves under side.. It would make this differenciation rather difficult. Terrestrial plants also benefit from CO² saturated water uptake via its roots, i guess this also goes for submersed growing plants, but for that it needs to be dissolved rather thoroughly, i don't see mist bubbles end up in the substrate at the roots.

Not so sure what to make of that demonstrative statement!?..


----------



## tiger15 (22 Aug 2018)

I don’t think aquatic plants breath through stomata which are non existent, poorly developed or degenerated.  I think Barr conducted control experiments to compare growth rate based on CO2 injection methods, so there is no need to distinguish O2 versus CO2 bubbles.  You can do a search to verify the methodology.  

There is a balance of how much mist versus dessolved CO2 to optimize growth, because too much mist means more outgassing.


----------



## zozo (23 Aug 2018)

Ok, looking it up, had to do that before i made assumptions.. Submersed form morphology indeed seems to change for most plants and use surface cells to absorb and secret gasses from the water. Than my simple brain says it still is a stomatous functionality, plant does the same thing using a different organ.. And badly dissolved co² resides in the water as a bubble, if the plant wants this gasious co² bubble, it needs to attacht to the surface of the leaf to make cell contact. In that case it is only logical that a pure co² bubble attached to a leaf results in more sufficient uptake by the cells its attached to.

Using logics i can only agree with the idea, it's obvious. As it is obvious that it would be a mater of chance that a co² bubble attaches to a leaf or any other plant part. Since the bubble wants the surface, pop out and dissolve into the atmosphere and is not going to travel around alot to look for a leaf to atach to first.

What throws me off the most and what ever method is used adding co² is how does one determine it's a co2 bubble that is attached to the leaf.. After all there is no visual difference in a co.2 and a oxygen bubble.  Than you also must be pretty good to be able to say that the beter results in this method are partialy related to bad dissolved co²..


----------



## tiger15 (23 Aug 2018)

The function of stomata is the ability to open and close to regulate gas exchange and moisture loss, critical for terrestrial plant survival but not aquatic.  Terrestrial plants have waxy cover on surface cells to limit gas exchange which is lacking in aquatic plants.  Gas exchange can occur every where on aquatic plant surface cells which function differently from stomata.

I can’t find Barr’s experiments on CO2 mist, but found this that cited his findings.

https://www.advancedplantedtank.com/diffuser_or_reactor.html


----------

