Sounds like spider mites to me. "Little white things on the bottom" is a dead giveaway. Get rid of the leaf a.s.a.p. and closely inspect the rest of the plant for the little buggers. If you see any more, add a small amount of dish soap to water and spray on the affected areas, hopefully that'll drown them. You need to make sure you get them all, because once you have an infestation they are hard to get rid of, short of scrapping the plants, cleaning and disinfecting everything, and starting over with seeds.This leaf is balled up, curled the opposite way, so what would be the underside of the leaf is making a little burrito, it grew this way since I got the clone a week ago.
Now today, after a close inspection, there are little white things on the bottom. It looks like grains of salt or sugar. I dont have them anywhere else on the plant but this leaf.