Plate ate sand?

[APBonds]

My plate coral (Cycloseris) has been doing well for the past month I've had it, until the other day when I noticed it was half way covered in sand. It looks like it had eatten some of the sand and now it's fleash is with drawn.
Anyone have ideas on why it would eat sand or is the sand iritating it.

Nitates 0
Po4 0.03
cal 420
kh 10
mg 1400
salt 1.024
diy leds
on sand in low flow area.

[seapug]

Most likely got buried by a fish or burrowing shrimp. It is probably contracting in an attempt to expel any sand it ingested.

[APBonds]

Yeah it still seems to have sand in its mouth, I've been tempted to turn it up side down and kinda shake it out.

[APBonds]

It's been about 3 weeks and it is still with drawn. It gets a little sand on it every now and then but it hasn't been covered up like the first time. I wounder if it doesn't like the sand so much that I should move it up on top of a rock, but then it might bail off the rock.

[elegance coral]

What's causing the sand to get on top of the coral? I'd simply fix what ever is causing this.

[APBonds]

Dimond head goby, hermit crabs. I wouldn't think sand would bother a coral thats supose to be on the bottom, but thats when it retracted.