i would go HPS if you can make it work. after a couple 100 watts the heat is pretty much the same. proper ventilation is the KEY.Hey fdd, you have been the only person to give some reasons that cfls are bad and scare me for my room, but in your own experienced opinion are cfls going to be hotter then hps? Cause i would like to do a 100w either cfl or hps per plant in my room. Doing this i need the coolest lighting source available.