Grey Stuff on Montipora

[jwwoodjr]

Any idea what this grey/white stuff is on my montipora? It appears to be on it but I can’t blow it off with a turkey baster.

 

[vetteguy53081]

Any idea what this grey/white stuff is on my montipora? It appears to be on it but I can’t blow it off with a turkey baster.

Hard to see on my phone but can be mulm or sediment
To find out, take a turkey baster and give the surface gentle blast’s and see if it dislodges. If not may be chrysophytes or similar