My RES is about 1 year old, he is around 2 inches long. Pretty much right after I got him (9 months ago) he developed white stuff on his shell that is still there. The white stuff does not come off when i rub it. He basks a normal amount. Milton has the right lighting and right water temp. The only thing I can think that it might be, is that I have hard water. But the white stuff is not all over his shell, and if it was hard water, wouldnt it consume the entire shell? I have taken a picture of it, so if anyone has any idea what is on it, will you please let me know?
Here is his shell...
Here is his tank in case it helps...




