Do hungry snails/crabs eat coralline algae?

[gte539f]

My coralline seems to be bleaching from the top of my LR, but it grows everywhere else just fine. Thought it might be the lights but when I was reading another thread someone put this link:

http://saltaquarium.about.com/od/aboutcorallinealgae/ss/coralline_4.htm

A while ago I bought 10 astrae snails to take care of a green hair algae breakout. The snails plus adding a GFO/carbon reactor did the trick. I also have about 6 blue legged hermits, I used to feed shrimp pellets but stopped doing that to cut down on excess nutrients. If there isn't enough food will the snails/crabs resort to eating coralline?

 

[greenbean36191]

No. Most of the grazing snails in the hobby have radulas made of keratin, which is softer than the calcium carbonate in coralline. Even if they thought it was appetizing, they can't scrape it off the rocks. Limpets and a few other snails are exceptions, but in the case that something is actually eating the coralline you will see bare rock left behind, not white coralline. It sounds to me like the coralline is just bleaching, perhaps because the clarity of your water has improved.