Plants look pretty good, maybe a little stretched, and IMO should be bigger with that light at that age. That light looks really far away for a 400w, but I understand that temps are an issue. What are the temps in there? Have you tried moving the light down, or tested with your hand to see what's bearable for the plants? I'd also mount the light sideways instead of hanging...

I think your next move should be to find a way to cool that light and your room. High temps will slow growth and flowering and could cause harmful stress.

BTW - CO2 is only effective in a sealed room.

Happy growing :jointsmile:
bigtopsfinn Reviewed by bigtopsfinn on . First time Small Closet Grow room (400watt Hg) Hey guys, This is my first semi-legit grow room using a proper lighting system. Using a 400 watt Hg Bulb on a 1000 watt ballast.(24hrs) I Started them from seed, i found the seeds in some amazing buddah :rasta: i grabbed last year and just held on to them. They have been in soil now for 3.5 weeks (promix) and i have given them some low concenration fertilizer that i had from some failed grows before its a 1-0-2 and made by GROTEK its designed for veg stage. So really the reason im Rating: 5