I have ordered bubble counters and will set up a few of those DIY yeast/sugar/water concoctions for CO2.

My concern is pH dropping during the nightime. I read CO2 should be off when the lights are? I was wondering if I could add an inline shut-off (like on air pumps) and just turn CO2 off this way or do you think with it being under pressure, this would not work? I'd hate for the line to pop apart and this thing bubbling on my floor all night.

What is the normal setting for a planted tank? I think I heard 2-3 bubbles per minute?

Any other idea's as to how to shut this bubbler off at night without unhooking it every day or is none of that really necessary?