Ok, lots of discussion on how many lights per plant, but not a lot on watt of light per plants, so here's my question, I like to use 400 watt lights, due to space, heat and output, and plant lenght, I use (1) 400 watt per 7 plants give or take, I cant really say beacuse I use more then 7 plants and lights though-out my grow rooms, Im just using it because thats how I think its spaced out, anyway, I was thinking of hanging CFL's lower down to give light to the lower branches, but not sure if it would make a differance, Ive tried 600-'s 1000's watts but they produce more heat then I can get rid of, I was wondering if i can do a S.O.G. on a large scale with 400's and if so how many plants per light, I have normal 8 foot ceilings. Want some advice to increase my yeild but not hurt it.