Do Nerite snails need shells?

In the wild, nerite snails have dark shells because there isn't much food. ... Snails need calcium to keep their shells strong, so a lack of calcium can cause the shell to weaken and crack. If you notice this then try adding calcium supplements, such as calcium sulfate, or use a calcium substrate.

Do Nerite snails grow their shells?

Freshwater Nerite Snails

They draw calcium from the water in order to grow their shells. Water that is too acidic, or too soft, will break down their shells over time. The shells eventually start to get brittle and even develop holes in them.