The only space i have is my attic. Im going to modifi the truses so i can have a 5x5x6 area. I will insulate and vent should not be a problem. So i guess my question is can I use a 1000Watt in that space?
I once grew in a 3'x4'x8' closet in my bedroom with a 1000 watt halide. I had a 265 cfm blower sucking air into the attic and cut a hole in the floor that pulled in air from under the house. Must have been 90+ degrees in there but man it produced.
I was using rotgut peters fertilizer in dirt and was consistently pulling 1.5 - 2 lbs per crop. Lots of light will sometimes make up for a primitive setup.
nsweedman, my buddy's using a 1000 watt hps in a room about that exact same size as your attic...its basically a walk-in closet in the master bedroom. Working just fine for him.
One thing that I don't think was mentioned, but is important in your case, is to rotate your plants, so they get equal exposure to the "sweet spots". Maybe once a week.