Scolys receding

[nly04]

Couple days ago, I notice two of my scolys look receding, and last night I noticed Nassarius snail claim into the scolys to take food (market shrimp) and leave white mark on those scoly, those mark look like they got stink and scolys receding. how to recover them and how to prevent Nassarius get food from scolys?

 

[Mark9]

Sounds like the snails are eating the dead flesh off the scoly?
Check your parameters, ca/mg/kh.
You feeding it?
I feed mine every Saturday.

 

[nly04]

I feed mine every other day. I think I should reduce feeding.

 

[TangingOut]

Whenever I feed my scolys I turn off powerheads and drop food away from the scolys for the nassarius snail and shrimps to feed for feeding the scolys.

I was having the same problem with the snails climbing into them to steal food.