Is my mystery snail sick

[Caitrob]

Hi I just realised my mystery snails shell seems to be eroding but the water PH is between 7.5 & 7.8

When I last got the water fully tested all the levels were fine and it seems to have only happened recently.

 

[shellyx]

Just feed calcium food, kale, spinach and hikari crab cuisine which is really good, add some cuttlebone into the tank as well.