Well I just recently had this very delima when I got my 1000W light. I had 9 little girls in soil under a 400W bulb about 3-4 weeks out from done, so here was my senario.
I had a 1000W MH/HPS digital ballast, a 1000W MH bulb, a 1000W HPS bulb, 6 girls grown at appropriate size for a 400W, 12...