I couldn't find them on any leaves, but there are many around the side of the pot. In person, you can hardly see the damn things let alone any spots on them.
Those things were crawling ( like a spider..like mites ive seen under microscope )..not flying...
Watch for webs at your nodes to your leaves..
I have a fungus knat problem going on but there black.
Im using soil..havent seen any harmful effects to my grow...just annoying as hell