ok so i have an 18"x18"x4' grow box, can i fit 4 8" pots in there for a whole grow & only veg till its 8-12" so it only grows 3ft?
theoretically you should be able to fit 4 ea. 8" pots in the space you've described. with a 4' height, minus the height of the pots and the space needed for clearance for the lights, you should have about 2.5' of vertical space for your plants. Fill up the canopy and then switch to a flowering light cycle. Good luck.