I believe im running the yield master 2 air cooled light. This is my second run with this light. First run I had three plants in a plywood box a little smaller than the closet im in now, and did real well. This time I had more room so I ended up putting six in there. It was a little tight but plants seemed to thrive. Anyhows I cropped one at least two weeks early and the colas where rock hard and all, I just wasn't that impressed with yield. Its not dry yet but by the looks of things i'll probably get ounce and a half, maybe a little more. I was getting that off a 250 hps. So what I was wondering is, say you get a gram a watt, does that mean if I grew one plant i'd get 600 grams and if I grew six plants i'd still get 600 grams? I guess to simplify my rambling question, I would like to go down to four plants if the yield would be the same. Because like you say, when they are crowded light doesn't penetrate to the bottom as well and not only do you end up with popcorn buds it just makes trimming harder. As far as the avatar goes,I doubt she really understands the power that ass yields. She could bring about world peace.