Feeding Springtails?

[Kurt]

Yes, the mites destroyed your fruit fly cultures. They prey upon the eggs and pupa. Once they get going the culture stops producing.

[Niels D]

I'm keeping them on coco fiber mixed with some of those red clay balls (can't remember the Englisch name) which people use for they're plants. Works just fine. I harvest them by putting a white film canister in the substrate so they could fall in. The white colour attracts them. If you let it stay over night you've got quite a bunch in your canister.

[Kurt]

The red clay balls are called LECA or Hyrdoton. Hydroton being a brand name, I believe.