is a 250w hps enough to carry 3-4 plants through to flowering? (possibly with some accompanying CFLs on the underside) and, could I use a 250w hps to veg my plants? or only to flower them? third question. for 3 - 4 plants should i use a 250w HPS or a 400w HPS my original plan was to use 4 85w CFLs to veg my plants and then I was going to put them under a 400w hps to flower. i am now a bit worried about how much heat a 400w will output and am thinking that the 250 would suffice. is there a benefit to using 400w lights over 250w lights when you are only growing a few plants? thanks to any who answer my questions! looking forward to posting here and growing better plants thanks to all of the posters here.
A general rule of thumb on these forums is 100 watts per plant, or 50 watts per square foot. If you were to grow only 3 plants, u might be able to get away with the 250 watt, AND some cfl's. But if you want the best yield for ur money, you'll definitely wanna go with the 400 watt hps, especially if you're gonna do all 4 plants. And though it's not quite as good as MH for vegging, you can certainly veg under your HPS if need be. As far as the heat problem, depending on the size of your grow space, you'll probably wanna consider venting, and exhaust to get hot air out, and fresh air in, all HID type lighting (hps, mh) will put out considerably more heat than CFL's. Hope this helps a bit! good luck
