How effective an external filter would be in supplying CO2?

[alextret]

How effective an external filter would be in supplying CO2?

I do not mean any special setup, just an external canister filter. Bacteria should be turning 02 into C02 as they breeze, as fishes do.

[Luke*]

Do you mean how effective is it when you pump CO2 straight into the intake of the cannister filter and it churns it up? It's pretty good but it can accumulate then spray out a whole of lot of bubbles at once. Also long term the carbonic acid can wear away at the parts.

If you mean in terms of just spreading around the CO2 fish produce then it depends on how powerful it is, the more litres/hour the better with 5x/hour being the recommended minimum. Fish produce very little CO2, not enough to get your plants cranking like they will when it is injected.

Hope this helps

[alanmin4304]

If you mean: 'Will the bacteria in the filter produce CO2 like fish?" the answer is no. There are many different types of bacteria. Some need oxygen, some need no oxygen and some can survive with both. Some will produce CO2, others produce methane or other wastes. The main use of the bugs in the filter is as users of nitrogen not for CO2 production

[alextret]

>'Will the bacteria in the filter produce CO2 like fish?" the answer is no.

I see. I've been reading "Dynamic Aquaria" by Walter H. Adey and Karen Loveland in which they claim that external canister filters are bad because bacteria in them produce CO2, which brings the pH down. I thought that this CO2 could be a good thing for some purposes. They did not have any data on that, so I guess since nobody is using external filters for CO2, bacteria do not generate that much CO2, after all.

[alanmin4304]

I may have been dropped on my head as a baby but I don't see why an external cannister filter would encourage the growth of any microorganisms that are different to that in any other filter. They are there because of the environment and food.

[alextret]

In "Dynamic Aquaria" they recommend the use of the so-called algal scrubbers (basically, just to pump water through separate tanks with algae and a lot of light, with growing algae binding nitrogen). They recommend not using any filters at all, to allow plankton organisms to survive.

They do present sufficient data to demonstrate that algal scrubbers are effective. But, I would not use an algal scrubber as it should be too expensive (high power bill).

But of course, all biological filters would have a similar effect on CO2. The bigger the filter, the more CO2 it would (presumably) add. But perhaps, it would still be not much.

[alanmin4304]

The point I was trying to make was that there are millions of different microrganisms out there and they do not all use oxygen and produce CO2. The main ones you are wanting will carry out various stages in converting nitrogen to nitrate. In that process they may or may not produce CO2. There will also be other bugs present which may or may not produce CO2 and take no part in oxidizing Nitrogen.