Here are my babies. The blue cups are anonymous bagseed and the purple cups are Nirvana Short rider autos. The other pics are of my grow space, 1K switchable ballast, and 1K veg lamp. I also have a 1K veg bulb: Babies - Marijuana Pictures, Photos & Videos - Grasscity.com Media Gallery Right now, they are under two 100W CFL's. If I flip on the 1K HPS now at 18/6, they will be approx 4 feet above the plants tops. Is it too soon for that?
It's never too soon to put on a HPS light. Make sure you can comfortably hold your hand between the bulb and the top of your plants. Personally, I wouldn't have the lights any higher than a foot above your plants.