Something is eating up my acro

[Africangrey]

This thing start stripping flesh on an acro that I acquired a week ago, doesn't seems like eggs from AEFW or red bugs. The process is kind of slow but I see this pest advance day by day in the past 7 days. Not sure if this will infest my whole tank.

I took the mass using a pair of tweezers and the texture is some sort of hard shell not soft to touch.

 

[Africangrey]

seems like some kind of snails but non of them were moving under the microscope.

 

[cypho]

It looks like sand to me. Probably held together by tube worm mucus.

It is possible you have an aco-eating tube-worm. But that seems unlikely. I would look elsewhere for an explanation why the coral is doing poorly.

 

[ReeferBee]

Never seen that before. Tell us about your parameters. Any swings in alkalinity? Other corals, other than sps, look happy?

 

[Pife]

Same answer that I gave on the other forum. It's sand.