Switched from Floros to HPS HELP!!!

Hey everyone I have 2 plants about 4 weeks old and they looked fine then I put up my 400 watt HPS and about 5 hours later they are drooping bad.

Would that switch cause that? I have the light about 3ft above them and the temps are about 75 degrees.

They are in a hydro drip system, PPM's are fine Ph is 5.8.

Any advice much appreciated!!!!!

pics would help. I would bring the new hps all the way to the top of grow to not stress em out. I dont know how many floro's u were using?? Hps will dry out soil faster also, maybe they need water? Pics..

Thanks Yota, I had a 2- 4fters with a cool and warm white bulb in each. And all my plants are in rockwool. I raised the hps light another foot and they looked a little better this morning after the dark period. I checked the PPM's and it was 1500!!!! Shit I'm not sure what made it spike but I flushed them and changed the water.

Pisses me off because my 2 bigger plants where bag seed but I have 3 white widow and 1 big bud that are about a week and half old. Hope I didn't nuke the little babies.....we'll find out.