ya thats what im thinking caused it maybe, a cpl months ago i was away and had a so call friend take care of my animals, well he dint take to good of care of him bc when i picked him up after a month the tank looked like it never been cleaned, but that was like 6 months ago and he has had clean water and tank since, im guessing he got it b4 and it started only in a few spots and i over looked it tell now. will the stuff i put on his shell help at all for shell rot, it said it moistrizes and and nutiences and minerals to help strengthen the shell