plants gone very droppy in less than 12 hrS

H guys,
Ive just noticed somethin that i dont know how to fix?? please help.......

Ive had my 2 hydro plants in clay pellets under a cfl 250watt for the last two months veging, i no its v long but suited as ive just moved house and also needed to get a good 250 watt hps and ballast, broke my last one...

Anyway, ive just changed over to the hps for flowering this morning, after comin home from work today i noticed that the plants were very droppy.. i dont think i had the light too close but anyway ive moved it back up to over 24" away now.

Is there any thing else i should be doin that im forgettin or any reason they would droop because of the change in light spectrum or somethin?? im watering the plants 3 times a day at the moment. (im also waiting on a drip feed system)....

any help please.. ill try get camera tomorr to get some pics up tomorr

The leaves are running warmer under the HPS, so my guess is the plant is still ramping up enough water flow for the new rate. I'm not at the grow but droop is quite often caused by loss of water pressure in the plant. Could be coincidence, but if they perk back up start moving the light a little closer every day.