# CO2 reactors



## Riverside Scaper (30 Jun 2021)

I've in tank diffusers and very quickly made the switch to an inline diffuser and had better results, but I’m getting to the point now where I can’t stand the really fine micro bubbles of CO2.

Have any of you used CO2 reactors to limit this and can you recommend any? I know Aquamedic make a CO2 reactor and there is a company in the Netherlands that makes some that are supposedly very good. Are there any pros and cons to a CO2 reactor? This a new step for me and I’m just trying to do my homework.

Thanks guys!


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## Toby C (30 Jun 2021)

This came up a few weeks ago, see the link for a discussion about options. 






						CO2 Reactor UK sellers?
					

Anyone know if I can get one of these in the UK?  https://greenleafaquariums.com/products/aquarium-co2-reactor-16-22mm.html  Cheers Paulo



					www.ukaps.org


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## ceg4048 (1 Jul 2021)

Riverside Scaper said:


> I've in tank diffusers and very quickly made the switch to an inline diffuser and had better results, but I’m getting to the point now where I can’t stand the really fine micro bubbles of CO2.
> 
> Have any of you used CO2 reactors to limit this and can you recommend any? I know Aquamedic make a CO2 reactor and there is a company in the Netherlands that makes some that are supposedly very good. Are there any pros and cons to a CO2 reactor? This a new step for me and I’m just trying to do my homework.
> 
> Thanks guys!


Hi,
  I have used the Aquamedic unit (which is actually an in-line unit) and it works very well. It works even better if you remove the balls. The downsides are that it is a large unit, almost a foot long (30 cm) and with many reactors they tend to accumulate gas inside the canister. This requires you to bleed the unit or to modify it so that the gas can be returned to the downstream flow. I've seen a thread somewhere showing a DIY version (much cheaper) and the mod to auto-bleed but cant find it right now. I'll search and provide the link when I find it.

The reason the diffusers cause so much fizz is because there is insufficient time for the bubbles to dissolve. You could try add a much longer return tube downstream of the diffuser to see if that reduces the fizz. The penalty of course is that longer tubes add friction so this could affect your flow rate. This can be ameliorated by removing a significant amount of media from the filter to improve flow rate enough to compensate. You don't really need all that media anyway in a planted tank.

Cheers,


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## Driftless (1 Jul 2021)

I have, also, looked at them but for the time being I am sticking with in-line units.  I run two filters on all of my larger tanks so I am not as worried about flow reduction but I haven't heard enough to switch yet as I don't mind the bubbles.  My Discus tanks are run CO2 lean so the bubbles are not an issue.


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## Mr.Shenanagins (1 Jul 2021)

You could also use a water filter like the cerges design uses, and just run the filter flow the way it’s meant to flow instead of the reverse way the cerges does. This will increase the bubbles contact time with the water in the filter canister and they will rise easily to the outflow. This will also stop any gas accumulation so you won’t have to worry about degassing. You will still get a slight mist but it won’t be like the diffuser.


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## Mr.Shenanagins (1 Jul 2021)

ceg4048 said:


> I've seen a thread somewhere showing a DIY version (much cheaper) and the mod to auto-bleed but cant find it right now.


Are you maybe referring to Tom Barr’s design? It uses a Venturi to recycle the extra gas


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## Zeus. (1 Jul 2021)

Riverside Scaper said:


> I can’t stand the really fine micro bubbles of CO2


Waiting for the end of CO2 period for best viewing 

I used twin APS EF2 in a DIY reactor setup, which worked well and tank completely bubble free and manged to get a 1.3pH drop no problem, in fact with the aid of twin solenoids/atomisers/reactors I was able to get the drop in less than 30mins -Olympus is calling

I have ordered a couple of Aquarium CO2 Reactor - 16/22mm which is being talked about CO2 Reactor UK sellers? which should be here soon which I intended to fit venturis, however having just moved having time to fit/mod them my be tricky as have lots of jobs to do and tanks are being a bit neglected ATM


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## ceg4048 (1 Jul 2021)

Mr.Shenanagins said:


> Are you maybe referring to Tom Barr’s design? It uses a Venturi to recycle the extra gas


Yes, exactly! That's the one. Thanks, I'll have to go spelunking to dig that one out. 

Cheers,


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## Mr.Shenanagins (1 Jul 2021)

ceg4048 said:


> Yes, exactly! That's the one. Thanks, I'll have to go spelunking to dig that one out.
> 
> Cheers,


Here I’ll save you some time!








						Dual venturi DIY External CO2 reactor
					

This unit cost about 20$ due to using Clear PVC housing, you can use solid 2" pipe if you wish.  You can find all the parts at any Orchard Supply Hardware or Home Depot.  Two: 2" slip to 1/2 threaded bushing  Two: threaded 90 elbow 1/2" barbed About 10 Bioballs if desired 12" of rigid...




					barrreport.com


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## ceg4048 (3 Jul 2021)

Mr.Shenanagins said:


> Here I’ll save you some time!


You Da Man!

Cheers,


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## Riverside Scaper (9 Jul 2021)

Thank you for the replies guys!


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## Riverside Scaper (9 Jul 2021)

Zeus. said:


> Waiting for the end of CO2 period for best viewing
> 
> I used twin APS EF2 in a DIY reactor setup, which worked well and tank completely bubble free and manged to get a 1.3pH drop no problem, in fact with the aid of twin solenoids/atomisers/reactors I was able to get the drop in less than 30mins -Olympus is calling
> 
> I have ordered a couple of Aquarium CO2 Reactor - 16/22mm which is being talked about CO2 Reactor UK sellers? which should be here soon which I intended to fit venturis, however having just moved having time to fit/mod them my be tricky as have lots of jobs to do and tanks are being a bit neglected ATM



Yes the end of the CO2 period is my favourite time to view the tank for now 😅

When you put the in-line reactor on the intake side of the APS filter, do you not get the trapped air noise?


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## Zeus. (9 Jul 2021)

Riverside Scaper said:


> When you put the in-line reactor on the intake side of the APS filter, do you not get the trapped air noise?



Depends on flow rate thought reactor - I use low flow rate so noise cant be heard at any time.


Riverside Scaper said:


> Yes the end of the CO2 period is my favourite time to view the tank for now



With reactors done correct any time is good, if flow is good in tank pearling is less also. Only see pearling when feeding fish as I turn my Maxspect Gyres off for 10 mins and Ehiem skim for 20 mins


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