How much should flowering plant droop at night?

Hey there, I've got an 8x8x8 flowering room that I built for SoG, but my WW isn't to flowering yet, so it was empty.

My friend gave me an extra plant he had and I threw it into flower last night. So now she's in the 8x8 all alone. I went in this morning with a green light (lights were off) and she is REALLY droopy.
She is in soil, under a 1000w hps. Watered 2 days ago, I've been watering every 3 days under a 400w MH during veg and she's been looking super healthy. 1500 PPM cO2 in flowering. Temps high/low were 71-76 (should be warmer once I turn on the other 1000w hps). Light is 20" away, air cooled with 735cfm fan. Nutes given will be cal-mag, pro bloom, liquid karma, and sweet.

I understand that plants droop a little at night and reach for the sun once it's up, but they're REALLY droopy. Do I need to water it more often now that it's under a more powerful light? Or is it supposed to be really droopy at night?

Thanks in advance

Lights go back on in 8 hours, so I'll make sure she perks back up around 8pm tonight (PST).

she will start sucking water up like a sponge now that you initiated flower.you said she was givin to you.its probably just the change in atmosphere and nothing to worry about.give her a few days and she will perk up

Thanks for the quick reply. I was given her about a month ago, just had her in veg. I should have been more clear.
How often would you suspect is necessary for water now if 2 quarts every 3 days seemed good for veg.

Also the change from a 400 mh to the 1000 can be drastic enough to shock thed plant a bit. Its just recovering at night.

Awesome, I won't worry then...yet
Thanks guys!

Ive never used CO2 but from what I remember reading (I think) 1500 PPM is pretty high and with that level temps should be high too, like 85F during light. The combined stress of switching to a higher intensity light and flower prolly has somethin to do with it, but if she perks back up during the day I don't think it would be a prob.. I usually weigh the container and use that to determine when the plant needs water, it takes away guesswork which I totally suck ass at. And I know exactly how much water is available to the roots at all times, as 1 gallon of water weighs about 8.5 pounds or so.