# How does a CO2 reactor work?



## VeeSe (Apr 16, 2011)

Hi all,

I just read about the basic assembly of a Rex Grigg reactor, and I realize that it's basically a 15" PVC tube that both the CO2 and the water flows through. What are the mechanics/reactions that make the CO2 dissolve completely in the water?

Thanks!


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## Sharkfood (May 2, 2010)

You're trapping the CO2 in water column so it either dissolves, or exchanges with the gasses in the water to raise the CO2 level of the water in the tank. The turbulence in the tube also creates smaller bubbles, which have a greater surface area to volume ratio, allowing for faster diffusion.


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## VeeSe (Apr 16, 2011)

And a simple 2" PVC pipe tube of varying lengths (depending on flow rate of canister) will get this done?


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## Sharkfood (May 2, 2010)

As well as anything else will do the job, and better than many set ups. The only real downside is that if air builds up in the pipe, it makes a sloshing noise. There are ways to prevent or lessen this, but in my opinion, it's not a real problem if the pipe is inside a stand.

I use one on my 65G.


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## lurrch (Jul 5, 2011)

There are other downsides:
-decrease of pump throughput
-leaks

Both of these issues are rather small; leaks can be avoided entirely if it's properly assembled and the pump issue can be helped by using straight barbs (instead of the right angle in Rex's original design). A reactor seems to be the consensus best method to diffuse co2, especially if you don't want a lot of bubbles or equipment in the tank itself.


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## HD Blazingwolf (May 12, 2011)

lurrch said:


> There are other downsides:
> -decrease of pump throughput
> -leaks
> 
> Both of these issues are rather small; leaks can be avoided entirely if it's properly assembled and the pump issue can be helped by using straight barbs (instead of the right angle in Rex's original design). A reactor seems to be the consensus best method to diffuse co2, especially if you don't want a lot of bubbles or equipment in the tank itself.


i didnt see a reduction in flow at all in my cerge reactor.. 
leak yes, my fault as i didnt have the rubber o-ring on 

also what used to be 3-4 bps in my diffuser is now 1bps in my reactor.. take note VERY efficient. easy to gas fish


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