Hello, I have a turtle and a white mold appeared in my terrarium, such a cover, not such a hairy one. It's mainly on the back wall (there I have such an artificial background - a wall - an imitation of a rock made of polystyrene, which is painted with a mixture of something with sand and so it looks like sandstone rock) at the bottom of the substrate and on a tile (which serves as a place for heating for a turtle ). Don't know how to fight mold by some biological method? I know that savo would help, but still ... Thank you very much for all the advice and answers :)