I had like 4 42watters, 3 26watters, 2 100 watters and a 13watt bulb, when I git 150hps I slowly removed all but 3 cfl's. I th ok ught it was gettin too hot, but now I got a badass fan that I added and I could put 1000watt hps and I know it wont get too hot. This fan is like a fuckin jet...