Please help me out seasoned growers... i have a hps which i plan on using for veg and flower. i have a few cfl light on right now, not enough light on thier own and the seedlings are starting to stretch, when can i safely turn on the hps? why is it bad to use powerful hps from the start?
I think you can put seedlings under HPS as long as they have a good distance between them,however I wouldn't recommend doing it. They cant handle getting close b/c of their sensitivity to the heat.
If your seedlings are stretching its because you either dont have enough CFLs, or they are not close enough. Fluorescent light is the best vegging light you can use besides a Metal Halide. I actually prefer them over Metal Halide because they dont get nearly as hot. If you keep your lights about 2 or 3 inches from the tops of the seedlings they wont stretch and they wont get burnt.