Id have to agre with TF Sos, your wasting your juice with lights off applications IMHO. Ive been running COs for couple years now. At first it was with a timer, 2 hours on when the lights come on to bring the room up, then 15 min on and 15 min off all the way to an hour before lights off. Now i run a sentinel and maintiain right around 1200 or 1300 for the cycle. As long as everything in your room is optimal, the CO2 will be a benefit. It will only perform as well as the weekest link in the setup. If lighting, nutes and or feed, water yada yada yada arent up to where they should be, the CO2 additon wont allow ur girls to perform to their max. Also alot of folks will let their rooms run hotter with the CO2 addition. Some even believe low 90's is doable. I for one do not follow that school of thought. I still run my rooms at 76/78 degrees CO2 or not. If everything is dialed in Sos, CO2 will def up the anty for ya bro, ive seen it time and time again and it works.
Ken