I bottom water every other day, top water on saturdays. No nutes/ferts. In Jungle Growth potting mix. 4 foot T8 6500K for light about 5 inches above the plants. They do get fanned pretty much 24/7 by a little 6 inch fan far enough away just to get them swaying a tiny bit. About 5 days ago the leaves started curling on a few babies. What is going on?