I can't tell if this is the start of shell rot or not. There are white swirly marks on the costal scutes that I suspect are either from abrasion or shell rot, but I am not sure. My greek tortoise likes to sleep in his hot hide, which is a terra cotta pot half buried in coco coir, and he tends to prefer to dig near the side of the pot when he is burrowing to sleep. I suspect the marks are either due to abrasion from the terra cotta pot, hard water stains left on his shell after his soaks, or shell rot, but I can't be sure. He is only 4 months old, please help!