Leafs curl because they cannot expel water fast enough to keep themselves cool. Lowering the temps will fix this problem
Thats what my grow bible says. The pic shows the exact same problem.

I have that exact thermometer/ RH meter. Its nice cause the numbers are big so you can read if far away easily.
CrackLemonade Reviewed by CrackLemonade on . Edges Curling Up Troubleshooting forum included hey guys, 2 days ago my plant's first 2 sets of leaves began to curl inward from the edges. its still showing noticeable growth and has pretty healthy looking green leaves but they keep curling up! it's first multi fingered leave is just growing and i'm afraid what might happen to those ones.. heres the troubleshooting questions to help clarify anything for u guys thanks for your're valuable time guys, i know u wont disappoint me :) H=Answer if you grow hydro or aero---hydro C=Answer if Rating: 5