Leaf curl on top leaves

Howdy all.
Can anyone offer any advice?
I have one of the top leaves of one plant curling down could it be to much light or too close to the light. Help it's one of my certain females. what do you all think.
Any help would be great.
Afro

sounds like over watering to me...imo...pics would help though

here is a pic hopefully. I vegged for 6 weeks and tallest 3 feet high. I water once a day and feed twice a week. The 8 plants are in day5 of sexing and and I would say that 6 are definite girls and the others look hopeful. They are pretty tall 3.25 feet. I am concerned about the distance between lammp and tops. The leaf curl is happening to the tallest. What do I do if they get too tall? Any tips would be great. first time grower and so far looking good.
Cheers from Afro (side show bob)