atm the homemade cfl hangs about 3 inches above the big plant and about 4 from the smaller ones, the plants still grow, if slowly. the light in the room is really well reflected down to the plants and none escapes, the room temp with the cfl's on is about 22, the heat the lightbox produces isn't enough to heat the room up too much, however i have no idea about the 300w cfl's as i dont have them yet but ill post readings when i get them and im more than sure it should be fine. time will tell and ill make sure to tell you everything, your such a help! i will flower as soon as i get em lights- i heard somewhere that females tend to grow smaller than males, and if this is the case, i think i can tell which one is female, not 100% sure tho, its just the only different one with much smaller spaces between stems. do you think 300w is too risky? should i go lower to like 200w? im starting to worry now :s you grow with cfl's? x