well we do run the A/C at 75 but I think it is off because the room runs in the 72-74 range during the day and about the same during the night Plus I will have two fans in the hood as well as the back will be completely open. This will be in the living room so the temp will be pretty stable and cool with a cieling fan. Like I said above this is not set in stone but for $280 I can get a CoralVue 175w MH with 2X24W T5 actinics or I can get a 4X39w T5 setup for $329 not a big price difference but big enough. Nothing set i stone I can always change my mind right before I purchase the lights. I relly do appreciate you alls help in making up my mind.