They look dehydrated. What are your temps and rH? How often and how much do you water/feed them. Any signs of pests? How close are your lights? Provide all the possible info you can to get accurate diagnosis.
A closet grow, 240w led full spectrum. Water once a week. Yep is 74 with 34% moisture. 1 month old. 2.5 feet from tops is where the light sits but I'm going to a 600 w hps next week. Feeding them general hydroponics off there feeding chart and ph'd water at 6.5