Grain mites in fruit flies

[Mystymantis]

It keeps happening. These pesky tiny mites appear out of nowhere like phantoms! I keep getting grain mites at least once or twice every year and am getting tired of it. How do you all keep grain mites away from your fruit fly colonies? Specifically they seem to like my Hydei flies but are also on the fruit fly colonies.
I have tried mite paper and it didn't work well. I have tried putting double sided tape on the containers. They still get in and still appear out of no where.
I clean out the colonies and start again to get rid of them and they are usually gone for a while but sometimes reappear. How do any of you keep the grain mites away and or get rid of them if you have a infestation?
Thanks!

 

[ANTdrew]

I set my cups on a dish of diatomaceous earth, which is basically microscopic shards of glass. If mites crawl over it, they die. Starting new cultures quicker than the mites can complete their life cycle is also important.
It is a much bigger problem when mites get into my ant colonies. I have been successful at eliminating grain mite infestations before by releasing predatory Hypoaspis miles mites into my ant setups. You can order them from Natures Good Guys, a biological control company.

 

[Synapze]

I basically use the same method as @ANTdrew and it stopped the mites from moving from older cultures to fresh cultures. I also smear a heavy line of coconut butter (or Crisco) at the top of the bin that prevents them from spreading to other areas. It ended most of my mite issues.

 

[Mystymantis]

I basically use the same method as @ANTdrew and it stopped the mites from moving from older cultures to fresh cultures. I also smear a heavy line of coconut butter (or Crisco) at the top of the bin that prevents them from spreading to other areas. It ended most of my mite issues.

Thanks so much for the advice! I will see what I can do to prevent grain mites based on your guys responses. Thanks so much!