I just purchased a 20lb tank...i have a regulator and was wondering how much i need to release for a room setup?
Ideally, you should purchase a controller to keep the co2 at the proper levels. They're expensive, but well worth it. They work by sensing the co2 ppm in your grow room and automatically keep the room at the pre-set level. If you cannot afford the cost (a good one is about 500 bucks) , the tank/timer method is used with moderate success. Here's a post that explains the formula to follow to set your timer/regulator. http://forum.grasscity.com/grow-room-design-setup/362511-co2-questions.html#post4256273
To use Co2 would you not need to match it with your lighting (the more lumens the more Co2)? If you by chance had CFLs, i can't see much good in adding Co2.
