I just built a 6ft high by 4.5x2.5ft growbox in my outside greenhouse( greenhouse gets too cold to use it in the winter. I was wondering if I can skip using the fluorescent lights for veg and just start off with the 400w HPS for the entire grow. Also do you think that the intake vent at 1.5 inches pvc and 4 inch out take with fan is sufficient? Thanks!!!
i'd add one more intake, whats the cfm of your exhaust fan.. and you can start off with a 400w, no problem, u must keep the light further away from young plants at first....4ft or more just to start...
250 CFM (I don't even know what that means) I can make the intake bigger. What size do you suggest? The air coming in is pretty cold. I've decided to get a switchable ballast and start the veg with a 400w halide.