On Thu, 26 Jun 2003 22:31:51 -0500, Eric Schreiber
wrote:

So yes, we can and do actually measure an increase in dissolved CO2
when using CO2 injection.

Right, and contrary to Dean's incorrect conclusion, the benefit is not
simply an acidic pH. If you lower the pH by softening the water and
adding peat (tannic acid), you get the low pH, but not the increased
CO2 levels, and the plant growth will not improve.

In fact, if you have very hard water, you can have a basic pH (over
7.0) with good CO2 injection. If you have very hard water with a KH
of 20 degrees KH, and you inject CO2 to raise the level to 15ppm, you
will have a pH of 7.6, and you will see the benefit of increased CO2
level in the plant growth, without the acidic pH.


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