Question

What is all this stuff over my foliage?

No idea. Can you wash it off?

Looks like it may be damage from spider mites? I check for 'em by pinching leaf gently @ stem, and sliding fingers up leaf to end. If you get little brownish streaks from the underside of the leaf, you've got 'em Hope not, fingers crossed for ya!

It is difficult to get off... it has been on some leaves of the plant for a long time. Since... about halfway through veg. I do not have mites. I recently had a small bug worm attack that killed two of my baby clones and tried to get at my other plant but thankfully it only took one top. I still havent found one on this plant, which is a bigger reason why I am stumped as to why it has leaf abnormalities.

just give it a good bath . little soapy water soft hand scrub then wash clean water . plant will look droopy after wash , just make sure shes supported until shes dry and it will stand straight up again in a few hours. ........................ usually black marks are from a fly the eat and spit up there food and its very hard to wash off.

Agree with kinddiesel.

poppycock, lol!!! that looks like thrip damage to me. check the backs of your leaves. they are very small and hard to see. kind of translucent...

Some kind of of bug bites, that's for sure.

I second Thrips. get some spinosad.

Mite damage and the black dots are fly shit.