Hi Breezy, welcome to the forum.
My plants, in a DWC set up, have been doing that 'pixie feet' thing, curling up at the tips and a little browning also. During my third grow (am on the fifth one now) they did the same thing, only worse. I learned that it was from nutrient burn. I was feeding the plants rather heavily during that grow. I follow the manufacturer's feeding schedule now and only have minor curling and very little browning of the leaf tips.
I'm not sure if that is the problem that You are having. Your plants look very good and healthy in the photos and the curling does not appear, to me, to be very bad, but it is all ways a good thing to pay attention and try to head off problems before they get out of hand.
Good luck with Your grow.