The plants look pretty healthy to me, although when you see the leaves folding upward (I think they call it "Taco-ing", as in looking like a Taco shell), it usually means that they are getting a little too much nutrients, like the Old Man said. What type of medium are you using and how much fertilizer have you been using? Fox Farms products sometimes have this problem from the amount of fertilizer that they use in some mixes, but it can happen with any medium with enough fertilizer mixed in. A little history on them, age, medium, light type, fertilizer... this info is very helpful when trying to figure out issues. A photo is always great, but other info can be just as important. Keep up the good work!