# Co2 = Killer?



## jimster (Jun 3, 2004)

Does anyone know the effect on the biological filter medium (good bacteria) inside a canister filter when pressurized co2 is injected into the input line? Will the co2 in any way destroy or weaken the bacteria inside the filter? It seems like a good idea if co2 were injected into the intake of a ehiem canister because the medium inside, as well as the impeller would certainly brake up and dissolve the co2 and shoot it straight into the tank. Would the gasous bubbles of the co2 cause the impeller to make noise like when air is trapped inside the canister?


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## MiamiAG (Jan 13, 2004)

I don't think so. I've done this in the past.

I think I've read that today's filters would be able to handle the small addition of CO2 without a problem. Noise shouldn't be an issue unless you are bubbling a lot of CO2.


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## Steve Pituch (Jan 25, 2004)

I think this is Tom Barr's preferred method (intake injection). If its good enough for Tom then..........

Steve Pituch


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## www.glass-gardens.com (Jun 3, 2004)

Steve Pituch said:


> I think this is Tom Barr's preferred method (intake injection). If its good enough for Tom then..........
> 
> Steve Pituch


In a balanced planted tank, I wouldn't even run a bio-filter, the plants ARE the bio-filter. I run Magnums with just the micron cartridge with no problems at all.


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## Bert H (Mar 2, 2004)

While I don't have a canister filter, I do inject my co2 into my ac hob filter. In over 2 years, I haven't had any problems. Every so often, it does 'burp' somewhat, and that tells me I need to clean out my filter sponges.


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## aquatic-store.com (Jun 23, 2004)

Many people who hae fully planted tanks run them without a canister filter s the plants do a wonderful job of keeping everything in check.
There is a possibility of to much co2 killing the filter bacteria i suppose though.

Marcus
http://www.aquatic-store.com


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## plantbrain (Jan 23, 2004)

Well if it's good enough for Tom Barr, that crotchety hogfarmer, then I ain't doing it!

Bacteria give off CO2, I really think their role is fairly minor unless you have a large shock added to the system over a short time frame. 
Generally the plants will out respond the bacteria.

Consider the biomass of bacteria(micrograms) vs the biomass of plants(100's of grams dry weight) in say 100 gallon tank.

Bacteria are faster, but when faced with so much more biomass, their role is very small.

So it does not matter, plants are the filter, bacteria are only for a back up(which is not bad idea either).

Regards,
The real "Tom Barr"


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## Error (Apr 16, 2004)

plantbrain said:


> Well if it's good enough for Tom Barr, that crotchety hogfarmer, then I ain't doing it!


Hogfarmer? I was thinking putty-faced applejohn myself 

Where does epiphytic bacteria fit into this scheme? Surely they grow on the surfaces of plants, wouldn't that place them in a better position to respond first?


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## Robert Hudson (Feb 5, 2004)

I don't think Tom addressed the question exactly, does C02, carbonic acid, kill bacteria? I understand bacteria creates C02 of its own just as plants do, but is the amount of C02 injected into a cannister filter enough to actually kill bacteria?


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## plantbrain (Jan 23, 2004)

You could try it on a non planted CO2 enriched tank so you coukld remove the plant influneces and see how much NO2 and NH4 are produced by keeping a heavy fish load or adding NH4 without fish.

Otherwise the effect of the CO2 on filter bacteria would be difficult to quantify in terms of reduction.

The plants tend to mask the effect on the bacteria due to NO3/NH4 uptake.

I think the bacteria are pretty tolerant of it, more so than fish, which don't seem to mind excess CO2. Lots of O2 seems to help and be more important.

Substrate bacteria, bacteria on surfaces etc are also influenced but are likely in the same boat.

The "practical" shows no issues with it regarding the filter bacteria near as anyone can tell. I'd not worry.

Hog farmer and _E coli _rancher

Tom Barr


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