There are many things it could be.

Like what type of water are you using?
What is the Ph?
What nutrients are you using?

Just a few questions I have more but those are a good start.
Zandor Reviewed by Zandor on . curling leaves? got no help in plant problems so i thought id try in here. i dont have pics coz im at a net cafe n shit but the leaves on my plant seem to be curling in and also droop. what could be causing this? i had a bad case of spider mights and thought it was just them, but the\yre long gone now and its still happening. the plant is growing in a drip/bubbler hydro system with a 600watt globe. any help is appreciated, cheers. Rating: 5