On Fri, 22 Nov 2002 19:07:07 -0000, "Iain Miller"
wrote:

The amount of CO2 in there in the first place is so small at 2-3 ppm that
there isn't much to lose & therefore very little effect can be had on the Ph
in reality.

PH does change with CO2 concentration so technically yes, if the co2 levels
get depleted to almost nothing then the PH will go up but not, I think by a
noticeable degree.


If you had water with a KH of 3 degrees, and a normal CO2 level of
3ppm, and then the plants consumed most of that CO2, resulting in a
CO2 level of .5ppm, the pH would jump up to 8.2. I've seen this
happen in my non-injected tank. It happens in medium-high light
situations. Simply running an airstone will prevent this from
occurring, and will maintain a steady 3ppm or so.


Chuck Gadd
http://www.csd.net/~cgadd/aqua