Help! curled leaves

I am in week 4 of 12/12 (flowering) and the leaves are curling under really bad. What could be causing it and how do i fix it?

pics would help

ive tried flushing it out for a week about a week ago and didnt see any results. I went through and removed quite a bit of leaves since i have about 27plants (bubba strain so they get full) so that more light penetrates down below. Could that be the problem? or could it be from over watering? they look shriveled and curled under? i dont have a camera right now so cant post pics sorry. thanks for the help