My room is 8x9x8, I am or 3 weeks from flowering, and I have hit the wall for my budget, I went ahead and bought everything i would need need and hit a wall cash wise before I could get into c02. Hell I am barely able to keep temp wthout running the a/c all day, so I figure some c02 will at least help them tolerate the heat a bit. I have buddes that own a paintball shop and had them give me a 5 lbs co2 tank, but it only has the regular twist top ball regulator on it. Normally i would just wait and wouldnt bother, but with the heat I feel like an honest swing in the dark would be better than no action at all. So basically this is my question. Does anyone know about how long, at the pace of a slow hiss, should I leave the tank cracked, and how many times throughout the day, also I am currently at 18/6.