Thank you everyone... appreciate the responses. I'll delve a little deeper with info...
I'm in coir & pretty confident I've traced the source to 2 bags of cococan croutons I got almost a year ago. Got at least 3 types of mites, though it may have been 5 or 6, springtails & 1 type of nematode. The reason I think the ccc croutons is that the nematodes were found under the bark of one of the chunks. Went downstairs to look up & 10 minutes later they were dried up & dead. THe ccc had moisture trapped in the bag. Upstairs, very careful with filters, never had a bug (still don't except my soil mites).
Definitely not springtails as had them too. These are maybe 1/4 the size of a springtail... so you can see why I'm having prob's w the pics... just can't focus in that small. I use a 25x microscope to see them w any definition. Definitely a mite... possibly a gamasid...?
They breed in the soil & seem to need moisture to stay alive. The only time they crawl on the plants is in search of new food/territory, but just die on the plants or crawl back into the soil. The rims of the pots look like tiny little freeways jammed with white cars...lol, funny. This is w the pops just blow up.
I tried the DE, but they're in the soil. I tried even mixing DE in a drench, but clumps up near the top, kinda like lime does. Thought the DE needed to be dry to be effective, but gave it a shot anyway. I can't tell if the DE barrier did anything as would find the dead bodies in other areas. ****, they live in my pipes now.
I killed them all except this one variety... a year later... sigh. Guess I should be laughing...?