I am growing in the same size tent using DWC and a 600watt lamp. I let my plants get too big in veg before I started to flower. Don't do what I did! For me, 4 plants took up all the room after I topped them during veg stage. Don't top them! This is first DWC grow and I am making mistakes. Still, I some grat cola's forming. I also needed to switch to an air cooled reflector to control tent temp. Without air cooled lamp I would have cooked my plants. Hope this helps. Good luck and learn.