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Re: Does carbon filtration remove CO2?

Pat wrote:

>I just recently set up (one week old) a 10 gallon nature aquarium.  I'm
also adding CO2 via the "do-it-yourself" yeast
>generator method. I run the output from the generator directly into the
>input of my power filter.
>My problem is that even using a two-liter bottle generator on a little
>ten gallon tank, I'm still only able to get the pH down to about 7.3 and
>with a KH of 4, that only gives me about 5 or 6 miligrams of CO2 per
>liter.  Millenium filters only use cartridges containing carbon and I'm
>wondering, is it possible that the carbon is actually stripping the CO2
>from the water?  Can anyone reccomend a good hang-on-the-back power
>filter that DOES'NT use carbon cartridges?  Maybe Aquaclear?  I have a
>picture of the tank here:

I reply:

As certain as am of anything I am sure that the carbon is not your problem.
The problem has to be with your CO2 system. You may have a leak or a bad
fermentation. To check for leaks clamp the end of the CO2 line and imerse
everything in water. You may also have a bad fermentation. The temperature
of the sugarwater should not be too hot when you mix in the yeast and you
should float the yeast for maybe 20 minutes before you mix it into the sugar

It is very difficult to manage the pH in a ten gallon tank using yeast/sugar
CO2. If you plan on putting fish in there I would be very careful not to add
too much CO2. Your fermentation recipe should have two tsps of baking soda
and you should use a really small amount of yeast. No more than a 1/4 tsp.
When you use only a 1/4 tsp. of yeast the fermentation will lose it's
viability quite quickly and you will have to add more yeast a 1/4 tsp. at a
time to maintain the CO2 production. I always use wine yeast so if you are
using bread yeast YMMV.

Surface agitation is pretty useful for controlling CO2 levels in a aquarium.
In the picture of your tank I think I see bubbles on the surface of your
water. This indicates to me that you might have quite a bit of surface
agitation. Even tiny amounts of surface turbulance will drive off plenty of
CO2 and prevent CO2 levels from reaching high levels. In a small tank this
is a good thing. If you are sure you are getting CO2 into your filter then
you should be able to dial down your surface turulance to the point where
the desired CO2 concentration is reached. I have used Aquaclear filters and
to reduce the surface agitation I just raised the water level in the tank.

Most people don't use carbon at all in their planted tanks as it serves
little purpose. I am not familiar with your filter but why can't you replace
the filter cartridge with a sponge.

Nice looking tank BTW maybe you should be gving me some tips on aquascaping.


from the Canadian suburbs of Windsor Ontario.