4 ft is where the reflective insulation ends. It can go up to 6 if need be. The tallest plant is 3.5 feet. the shortest is that bushy looking indica plant coming in at 2 feet tall (all from the floor up). I definitely pulled the flowering trigger too soon I suppose. I got the jock horrors and wonder woman much bigger before I switched to 12/12 (also let them go about 6 weeks in veg I think) which is probably going to beef them up a big, They just started to mega-stretch and are just taking off. THere are two small ones, I tried to clone an NYPD (not that it worked well, but it lived) and I have a super small Jock Horror. I may tossed the clone cuz the leaves look fucked up (shape-wise) and from what I gather that may me a hermie.