Just want to know what others do with their Co2 at night with Ph controler. Do you all put your Ph controler in a timer or do you leave your ph controler and have a set PH?
assuming you have your co2 set to your ph controller set your ph controller on a timer so that it turns off the co2 supply when your lights go off. plants don't need co2 at night. O2 is a plus however!
CO2 at night with PH controler 
Linear Mode
