Nute Burn?

and the spray it's still on leaves like a powder and that's way looks like a mite... i think so..

that burnt stuff at the top is from when you sprayed the liquid on it while your lights were on, or it wasnt in the shade.

you have spidermites dont worry their easy to kill in seconds, read my sticky post, its a sticky in the bug forum, riu forum>MJ plant problems>Bugs. i'll make it easy for yah, heres the link https://www.rollitup.org/bugs/462592-dirtysnowballs-method-destruction-spider-mites.html