re: pH fluctuations in yeast CO2 setup

>From: "T. Misiak" <misiak at fsu_fsufay.edu>
>	o my light is only moderate, is the CO2 at these levels even
>helping things enough to justify its use and the instability of Ph it's
>causing at this time?

My bet would be that it helps.  You can always experiment by turning
off the CO2 for a couple of weeks and monitoring the growth rates of
your plants.

>	o I can't afford a "real" CO2 setup, if I continue using DIY what
>can I do to eliminate Ph fluctuations and stress to my fish and plants?

Do your fish show signs of distress?  If not, why bother?

When using yeast, you can do very little about controlling the
variations in the rate of CO2 generation.  But there are things you
can do to control the rate at which CO2 dissolves.  If you use
something like a Tetra bell, the rate at which CO2 dissolves is
proportional to the area of contact between water and CO2 in the bell,
and as long as the rate is high enough to keep you from running out of
CO2 in the bell, this is independent of the rate of CO2 generation.

               |              |    | |
               |   CO2        |    | |
               |              |    | | <------ Vent to let excess CO2 escape 
               |              |    | |
               |==============-----  |
               |   WATER      -------
               |              | 
 CO2             | |
 from      ------  |
 generator ---------