I've had my turtle for a couple of years now...and I take great care of his tank, clean it all the time...and he seems to be in perfect health, except that I've noticed over the past couple of month his shell doesnt seem to be doing so great. it looks like it is almost corroding....the edges of it are thinner than they once were and it even appears as if a small hole might be forming in a particularly thin area of his shell. I'm worried about it and I don't know what to do to prevent this and reverse what's already happened....any suggestions? or should i talk to a vet?
sad turtle shell


