BLUE TONGUE SKINKS

My Bts (6?) Ari has these small grey mites in his enclosure, they aren’t (as far as I can tell) in his mouth or his poop, nor do they seem to be crawling on him, but they are EVERYWHERE, there’s tons of them crawling on his stuff, in his water bowl, on his food, in his substrate, even crawling out of his terrium onto the table. I’m worried and I don’t know how to get rid of them, I’ve changed his substrate, cleaned his enclosure too to bottom, I’ve cleaned his (fake) plants and climbing things, my mom even helped me use bleach once to clean his things (we closely followed a tutorial on how to use bleach in a reptile safe way). We have tried 2 or 3 different brands of substrate, and they keep coming back. I use coco fiber substrate, currently using eco earth, I’ve used I think reptichip in the past. I’m worried, as is my mom, he’s my first reptile (we got him from my mom’s friend’s roommate two years ago, who got him a few months prior from a collage prof that passed away, so I have no clue on anything from his life before I got him) and my parents have no experience and over this past week or so the mite population went from 0 to dozens and I don’t know what to do.

They are more than likely springtails and are harmless to reptiles. Springtails are tiny and long while mites are sort of round. The black mites are the ones to worry about, seldom found in long term captives.