Serrated edges pointing up, leaves droopy.

Hey Growmie, When the serrated edges of leaves curl or tip up like that, it's often a sign of temperature stress, overwatering/root problems. Still, in your case, it could be because you are running a 24/0 light schedule which isn't giving the plant any time to rest, try going to an 18/6 light schedule and see if that helps at all.

Go to 18/6 and give your plants the sleep that they NEED, growing at 24/0 is a big mistake.

Leaves getting a taco look is heat. With growing in coco. I woukd drop your ph from 6 to 5.8. Check run off ph for 5.8 as well. Coco is high irrigation and is always suppose to be wet. No dry time.