Cork bark, I must see if I can by it, if not, I'll try to make it myself. My season is over, so now I have time. Today I saw some external filters in a pet-shop, but they are toooooo expensive, but I saw how they work and decided, that I'll just copy the system (during the winter). I wrote some veterinarians and have now a lot of contradictory answers

Somebody wrote, that if you don't have a place where your turtle can place her eggs it is considered cruelness. Du you have such a thing? Feri is courting all the time and I wouldn't like to have eggs.