Uncle Ben,
I would love to be a test case in increasing yield. If you have time give me some suggestions.
I usually flower 6 plants in a 4' x 4' area.
Lighting is 400w HPS....standard bulb.
I I run a circulation fan (but in no longer oscillates)
I run full power FF nuts including the solubles. I run one feeding of those according to the chart, then plain water the next feeding and so on
Temps usually stay in the upper 70's and a RH of about 30% with lights on
Lights off RH varies, and temps get to low 60's
I let my girls grow natural...i.e. no top no FIM etc.
The pot I use to pop my taproot in is where they finish....i.e. I do not transplant.
Pots I use are probably 10" in dia. I would guess a 1 gallon or 2 at best.
I use FFOF soil.
VEG
I already know your not in favor of 24/0 lights, but that is my current setup.
I try to keep 6 in there as well with 2-26w CFL which have the more white appearance, and 2-42w CFL of the more orange color
I only use water while I veg because 1) FF feeding scedule is too fucked up for me to keep track of who got what, and 2) I figured the soil could sustain the plants until they go to flower.
Yield on 6 plants is almost always 6-7oz.
It seems as though I could improve on that I just don't know how. Any help is much appreciated.
EDIT: finished plant height is about 24" for hybrids and up to 30" on Sativa leaning. I also try to veg long enough to get 10-12 nodes before flowering. A little less for Sativa due to height. I don't move my light I move the plants. I try to maintain the tops at no closer than 6" from the protective glass on my light hood.