On Sat, 26 Apr 2003 03:27:06 -0400, Greg One issue that you may
investigate is if you are running electronic
ballasts, you MUST keep the pH sensor wiring (and anything else
electronic) away from them, the tubes and the wiring. The high
frequencies they operate will radiate into surrounding wiring and
effect the accuracy of the units.

This explains why the temp probe and the pH probe fluctuate when the
lights go on or off........they are about 18" from the ballast that is
mounted in the hood (Ice Cap 660 Yea baby).

I will move the probes deeper into the tank.

The other cycling that happens when the controller attempts to turn
the CO2 off happens when the lights are off as well, so I appear to
have too issues. Wow. I should go back to just turning the CO2 on
with the lights or leaving it on all the time.

I like the idea of using the probe, as you can target the CO2 ppm that
you want based on your kH.

This tank also has an under gravel heater so there is a lot of juice
floating around.