Any idea if something is wrong with my astraea snail?

[ejp1288]

Here he is next to a turbo snail. Astraea was doing really good for a while but has now just been down here. Any ideas what’s wrong? This is in my saltwater tank.

ALK: 126
Calcium: 382
Magnesium: 1337
No ammonia or nitrites

 

[ColorMeGone]

Mine will stay in one spot more than he's moving. His favorite spot is next to the wave maker. It think he likes the vibes and he moves back and forth for a couple days at a time. lol. Mine are in around 10 N03 and a .1 P04. Cal is around 420 -430. They need food and Cal. to grow their bodies and shell in my book.