wat are these plants doin??

alright this is my first time doing purp diesel, im doing 18 hour days and most in about my 3rd weak. Throught out most of the day the leaves are standing up looking good but for a good few hours they seem very droopy. Stems and leaves are just dropped and im just wondering why. if anyone could help me out thanks.

I'm awake how about some pics?

when are the droopy? Morning right after the light comes on? mid-day? or when they are almost ready to sleep? Whats up? Need more info buddy...