Tiny round white bugs invading FF cultures

[Tony]

they are just white in color. where can i get mite shelf paper?

thanks guys. any idea where they come from?

Here is one source: Anti-Mite Paper, 18 in x 10 ft Roll - Insect Genetics - Genetics - Life Science - Carolina Biological Supply Company

They often come in on the dry medium, and also get transferred when seeding new cultures. Discarding cultures after a month can help to reduce their numbers, but it is pretty much inevitable that they will show up.