I was planning on growing nine plants under one 600 watt Hps/Mh convertible lamp in a growroom but after some thought I am reconsidering growing only six as light intensity deminishes when plants are placed further from the source. Does anyone think that six plants closer to light will yield more than nine plants spread further? What would be the optimal amount of plants under one 600 watt grow light. Space is not a problem as I have plenty of it. Any suggestions greatly appreciated.