Hey,
just to say if you they have come from under a cfl, (250w or below)and have then placed directly under a 600w , thats probably to blame.
Just like a plant should be hardened off when going from indoor to outdoor, the same can be true for cfl to hps. Especially if there is a 200w difference. I see in your snap that the bulb is down close to them, keep the bulb a good 3 ft away for first two days then slowly lower.
I run a perpetual with cfls in veg and a small hps in flower room, and i have stupidly put a plant from under cfl straight under the hps, wont do that again. Always start them on the edges then move in if you understand me. I think they are stressed from too much light. They should recover in a week,
Also the fan could be, but doubt it, removing to much moisture from the leaves,making the stomata close,therefore making them droop. If its not an oscillating fan have it trained for between the hps and the canopy, then get another to strengthen stems. Or move it everytime you go in there and reset it when you leave. In fact i just looked at your pics again, so you do have two fans, id just use that oscillating white one for now then use the black(and i presume non moving) one for when they are abit bigger.
Sorry but no one asked what your temp is, would be intrested to know. Someone else said it, whats your light schedule? I take it you are still in veg, hence the small plants, so my next question would be are you using a 'dual spectrum' hps? Or just a standard hps?
Also to give you an idea of how hot those leaves are gettin you should sit your digi thermometer on the rims of the pots. So its facing the light. If you got your fans working correctly then when its on the rim shouldn't be to much different from where it is in that first picture. If it is that could be a problem..
sorry if its long winded or that, just would like to cover all the bases.
Anyhow take it easy and best o luck. I think you will love stepping up from cfl to hps.
