No 4 at a time is what "I" found to be the best for me,,,,,,,4 plants in 6inch blocks,,,,, im thinkin of trying these 4 inch blocks I got and do a few more !!! I just couldnt see more than 4 at a time with the 6inch blocks,,,I would think they would be fighting for the light THEY GET SO DAMN BIG !!! with 4 every girl get her own corner to do her thing,,,,, the noize ????? You will hear it being in the room with it, but i have 2 Trinty systems So I have many fans going at once. Hmmmmm The fan over the stove,,,bathroom fan and not the quite ones,,, I mean their is always a fan running , with the light on 3 fans are going per box !! your going to hear it !!! As far as the pic above I coundnt see how that would help with flowering,,,,,only Veg and seeds !!