I've been seeing vet about this and my vet told me there's nothing I could do...but I want to ask if you have any other opinion, my turtle's plastron has white patch on there, most people(including my vet) told me it's because of the water mineral build up, but I've ALWAYS been using the filtered reverse osmosis water for her(never tap water) ever since 2 years ago but the condition only gotten worse and worse, I'm afraid if I don't do something her shell might break off....can someone please tell me what I can do? do any of you have similar issue?
*don't worry about the black patch on the right, that was from a bacterial infection about 5 years ago and it was cured, but the scar is still there
http://www.fx.clemson.edu/~ychiu/turtle/shell01.JPG
http://www.fx.clemson.edu/~ychiu/turtle/shell02.JPG
http://www.fx.clemson.edu/~ychiu/turtle/shell03.JPG



