You should be able to squeeze 12 in there if you left the center 2x2 area semi-clear for the light.

I wouldn't switch bulbs, especially since those that do switch in the last two weeks of flowering switch from HPS to MH, not the other way around.

Going vertical, you should expect well more than 4 oz per plant.
khyberkitsune Reviewed by khyberkitsune on . Indoor Grow Box Set-up Here is a quick layout on my ideal grow box. Im going to build a custom cabinet type grow box. As you can see in the photo its 3'x3'x7' and I plan to use a 4" exhaust inline duct fan with a carbon scrubber, im not sure what size intake vent hole yet, 400w HPS lighting, 2 CFL side lights, and a circulating fan for strengthing stems and in case I need to cool down the temp a bit. Any ideas on what I should add or change? Any suggestions on how many plants I can fit easily? Rating: 5