# Eheim canister with built in Co2 reactor



## IUnknown (Feb 24, 2004)

Over at the planted tank people have been using the Eheim Model 2227 wet/dry filter to inject Co2 rather than oxygen into the cannister, eliminating the need for a Co2 reactor.
http://www.plantedtank.net/forums/showthread.php?t=1127


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## pineapple (May 4, 2004)

I've been wondering for some time whether it might be possible to adapt an Eheim Professional cannister filter in some way to remove the necessity of an in-line reactor. I'll have to look at a 2229.

Andrew Cribb


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## gpodio (Feb 4, 2004)

A nice idea if you already have one but that's an expensive CO2 reactor if you had to buy one for the purpose. I don't know about you guys but I haven't noticed any difference what so ever between an inline reactor and feeding directly into a canister, my CO2 levels remained identical regardless of which method I tried.

Giancarlo


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## Raul-7 (Feb 4, 2004)

gpodio said:


> I don't know about you guys but I haven't noticed any difference what so ever between an inline reactor and feeding directly into a canister, my CO2 levels remained identical regardless of which method I tried.
> 
> Giancarlo


But isn't there a risk of C02 gas getting trapped in the impellor, causing it to run "dry"?


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## gpodio (Feb 4, 2004)

I guess there is if your canister is prone to this. I'm using Eheims and I've yet to see one airlock, even the very old ones expell trapped gas very well. I did have an old fluval that did airlock on me and needed a little pat on the back to burp air out after servicing but I'm sure the new models (rectangular ones) have solved this problem. Using pre-filters on my canisters I get a lot of gas pulled out of the water from the negative pressure inside the canister when the pre-filter is getting clogged, it really puts the anti air-lock route to the test and the Eheims have yet to fail. The only problem I've had is when disconnecting the canister for a long time the intake tube gets filled with gas and looses syphon, obviously this isn't something that would happen during operation so it's not really a problem.

I have no experience with other canisters but I haven't heard any complaints and I know many people inject CO2 directly into their canisters.

Hope that helps
Giancarlo


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## IUnknown (Feb 24, 2004)

The Eheim Model 2227 has a special chamber for the gas, so that there is no chance of breaking the impeller.


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## pineapple (May 4, 2004)

Some data:









Andrew Cribb


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## IUnknown (Feb 24, 2004)

So you would connect the Co2 to the breathing tube (3rd tube). The only thing I don't think I would like is that I think the cannister creates a wave like motion from the chamber filling up and emptying. I don't know if it would be neat, or a distraction having your plants swaying back and forth.


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## wantplantsnotwork (Nov 17, 2004)

Since I have the 2229, I posted these questions on TPT, since there are at least two people there that have done it.:

1) Does the cannister still cycle? I thought you might need some sort of bladder to act as a lung to accomidate the pressure changes to allow it fill /empty?

2) CO2 loss through the Eheim input tube. Did you run the C02 tubing directly to the cannister, (with a one way valve?)

3) If it does not cycle, do you get occasional 'burps' coming through? If not, I would think it would be a fairly efficent reactor.

4) I ask, because if this does not work, I would be forced to get either a 2228 or ebay clone, and an additional reactor. I may need the additional cannister anyway for circulation/filtration on a 90 anyway. I just thought that
using the 2229 as a reactor may be an elegant solution.

5) If it does cycle, does the bubble counter not remain constant? I envision it going nuts when the cannister is evacuating water, and creating a low pressure, and slowing way down when the cannister is filling with water, and having to act against the pressure of that.

Oh, I read that CO2 gas, over time, hardens plastic. Would this be a concern to any of you reacting in your expensive Ehiem.



No one had a response.

When I plug up the breather, the filter does not cycle anymore. It still will probably work as a reactor. 
I wonder how much CO2 it will burn off if I use it conventionally, and use the reactor I just bought at GG? 
If a balloon would not be so CO2 porus, I would thiink it would be a great solution, it could expand and contract with the breathing cycle.

Maybe in this application the cycle is not so important anyway...

Peter


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## Raul-7 (Feb 4, 2004)

I can't answer your questions regarding the wet/dry 2229, but I can answer your other questions. 

You're better off buying the 2228 than wasting your money on a wet/dry, after all you're setting up a planted tank and you wouldn't waves going through your tank. That would basically let C02 dissipate even faster. Plus, wet/dry's don't provide effecient mechanical filtiration and they're expensive. I suggest you use the 2228 with an inline reactor or you can simply inject C02 into the canister as Gian suggested.

BTW, where'd you get a 2228 from? I thought they don't make them anymore, or at least that's what I thought since I never saw one anywhere. :?


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## wantplantsnotwork (Nov 17, 2004)

I would not be wasting any money, I already have a 2229, for the last three years or so. Excellent filter. I have it on a heavy stocked 55, and it eats up the pollution!

The wave is a misnomer. There is none, the spray bar is below the surface of the tank. On a 55, it changes the level about 1/32 of an inch on a cycle. But you can set it up depending on your taste so that the spray bar sprays on the drain cycle by setting it up above the water level.

I bought a ehiem clone on fleabay. Still waiting for it to arrive. No 2228, although I have seen a few show up on ebay.


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