Just set up an automated CO2 system, a couple questions...

I finally decided that Flourish Excel wasn't doing the best job at
maintaining my plants. No DIY setup here, I went all out and set up a
CO2 reactor, a tank w/ solenoid, and a pH computer to shut off the CO2
if it drops below 7.00.

Plants range from Giant Valis, Cambomba, Hornwort, Moneywort,
Anacharis, and Crypts. Fish are fancy goldfish and some bushynosed &
rubbernosed plecos. Tank size is a 42 gallon hexagon.


-- I currently have CO2 going at about 2 bubbles per second. Is that
about right?


-- I have the system set to shut off if pH drops below 7.0. I
typically try to buffer to around 7.4. Does that sound like I'm doing
the right thing?


-- Finally, I have the system set up on a timer so that it shuts off
completely at night when the lights go out. (I have the lighting set
up on a timer as well.) It's my understanding that plants don't use
CO2 at night. Again, does that sound right?


I appreciate any help!