Growth of its shell and strange actions

[brookew5712]

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Hi! My snail started to grow its shell from April this year and the new-grown parts are more white and uneven than its old part. I thought this might caused by that I fed him calcium powder. 
Also, he frequently chewing(? I am not sure if it’s chewing) his shell.

Can anyone tells me is this normal?

[pasi9]

You may be right. It could well be caused by too much calcium.

It's best not to mix calcium in their food, they aren't able to regulate their calcium intake if you do that. Just leave calcium out for them and they will help themselves as and when they need it.

I wouldn't worry about the chewing unless he's actually making holes. Snails often "chew" or groom their shells, especially when they have new growth. He's probably just trying to smooth it down.