my plants whats wrong

they curling at tips and turning black or brown a little idk please help

Looks fine at the moment, a little droopy bit it's ok. Only water when needed, but I can't really tell. Please provide more info . What kind of soil, light, nutes if any, etc..thanks

Are they in coco coir? They look good honestly what ppm or ec u feeding

Looks like those girl may be ready to move up to a bigger pot. Other than that, they look fine.

too spindly. your lights r too far, your internodal spacing is like 2"