Leaves taco curling bad any suggestions

[Elliotw074]

Wats happening to my babies curling bad

 

[growsince79]

Light or heat stress

 

[Beachwalker]

Wats happening to my babies curling badView attachment 1033969

First thing I recommend is that you check for mites with magnification, it can also be caused by light or heat stress as mentioned above have you made a change to your lighting or moved your lights closer recently? and what's this white stuff, is that camera flash?