I'm using a 400 watt mhl/hps light in a 6" cool tube, In a 32"x32"x63" tent. 2, 5 gallon DWC buckets with 4 plants (One in one bucket, 3 in the other) I plan on culling them down to two when they all get a little bigger.
I have one small fan for the plants, and 2 pc fans for just moving air...