600 W elec ballast and5x7x7 room

I am gonna finish off 19 plants in this room in Dec-early Jan. I have Hybrids and Sativas hence the timing. I have 40 clones which are currently vegging that will go into the room once the current crop is down. I am gonna do a perpetual grow. What I'd like comments on is, do you think it's better to have 9,12,16 plants in the room for maximizing space and light? I was thinking of fewer large plants or more smaller plants, but I am conflicted. I wanna try to get 2-3 weeks between rows to be harvesting consistently come March and April and taking cuttings from the clones while in veg. I don't use CO2 and can't see myself doing so in the forseeable future. I have air movers and filters and lights which can keep me going. But I am working on maximizing output. I currently use Fox Farm O.F. or a non pre-fert peat based medium and give Fox Farms nutes according to schedule with a lil pH down to control the soil pH for uptake. I also use Unsulfured molasses in the last few weeks of flower for carbs to pack on extra weight at the 1 oz to 1 gal. rate.

I know this was a few days back but I need to know----do you flush according to Foxfarms schedule? I am just starting some girls out and using FoxFarms for the first time. I also am using Pro-mix with 1/2 cup of lime in each 3 gal container. What do you think?

I start flushing when I believe a plant is getting within the 2 weeks of completion area. I wanna try to get as close to clean as possible before I start the cutting and drying. This usually varies from plant to plant since I have so many different types.