This is just a suggestion. If it were me if do a little research on the subject. But It sounds like you arent getting rid of the mites. It will definately be almost impossible to completely get rid of them using Thr method you are. But... Have you ever heard of Hypoaspis? They are a type of predator mite. Def worth a look. Holistic and when the bad mites are gone they kill themselves off. I think something like that would get rid of the mite problem. As I know they need a 1/2-1 inch of sub to borrow into and colonize. You mix 2 tbs of the vermiculite with the good mites into your sub and they eat the bad ones. I dont know much about
The crabs but this seems like it could be a possible solution. You can get them online. I looked up a link not to long ago. I'll try and find it for you.
Hope this helps.
Morgan

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