I have a mystery snail, I've had him for a while and it kind of looks like his shell in cracked a bit. Is there something I can put in the water or a product I can buy to help it repair or should I just leave it? I'm not completely sure if it actually is cracked or chipped cause it looked like that when I got him just over a month ago but looks like it might have gotten worse since he got bigger and regrew his shell.