CO2 advice

[martym]

Tom- There isn't that much of a swing when the lights go off. Drops down to around 7.8 by 5am.
Chin- I have been thinking about a Kalk RX and a Auto top off. Just thought that the 2 combined would be over kill. I like the Cal rx due to it's simplicity.
Tang Daddy- I have a PM cal rx. There is one line going into the tank. The rx is set to the tank Ph. When the MD Ph drops below 8 the Rx turns off, but when the MD Ph goes above 8.01, then the rx comes back on. the effluent out of the rx is 6.7 when it is on. I have the drip into thank around 1.5 drops per second.

So it sounds like I shouldn't worry about it then. Thanks everyone for your help.