Well if your worried about heat issues or you don't have good ventilation you should look into LED or T5's, CFL's are good but will get hotter than both LED or T5's. You should have some kind of fan, preferably an inline fan, drawing fresh air from outside the tent, perferably fresh air from outside if possible. I will be running 6" ducting from a custom vent (2' piece of plywood with a 6" hole in it) in my window and it will have a hepa filter for dust/pollen etc. You know there are some pretty cool DIY cool tubes ideas in the DIY forum, that would be your best bet is a HPS in some kind of enclosed air cooled reflector, hope this helps.I'm using a tent I bought from the local hydro store. 2x2 rectangle with a lot of ducting fittings and a zippered front. About 6' or 7' tall. I have used 340 watts of cfl's(4 85 watt bulbs). I am wondering if I should switch to a 250 watt MH. I'm trying to maximize my output and think that the MH light will penetrate deeper into the canopy. What light should I get to maximize my harvest in such a small area(should I just keep the cfl)?