I also have a 4X4 tent used for vegging and flowering. I use a 600W HPS and sometimes switch it to 1000W. I put in 19 2gal. fabric grow bags during each grow. I also have a oscillating fan on deck and a inline fan connected through my reflective hood. Gets a bit crowded, but I like to see how far I can push it with different strains. The Kush, Afghanis and Hybrids seem to do the best in close quarters. I also use my 2½x2½ tent, 400W conversion bulb if not vegging , also using 9 2gal. fabric grow bags.