J: growing in a confined space like a tent presents some unique problems, namely the heat generated by your lights and air circulation. For the last year I've been growing in a 2' X 4' tent with T-5's and I find that if you get a fixture or fixtures large enough to completely cover your grow and you keep them close to the tops of your plants I think you'll be very happy. I hope that helps. Hank
In my limited experience I'd say at least a 600w and potentially a 1kw. I say that because 1kw isn't quite enough for my 4x8' tent, something a few ft smaller would be perfect for the light
J: I think it depends on how big an area you intend to light and how much you intend to grow. I have a 2' by 4' by 6 1/2' tent and two T-5 fixtures 4' long and 4 tubes wide light it up like a car lot at night without the heat you get from almost any other form of lighting. I'm a legal medical approved personal grower in my state so I am no threat to anyone. If you're a personal grower remember you have no one to pass on your overhead to. I hope that helps, Hank