Interesting growth on coral

[Tcox]

This appeared seemingly overnight, although I likely just did not see it. Any clue what this is and how big of an issue it is?

 

[billdogg]

if you are referring to the semi translucent things amongst the zoanthids, they could be either Aiptasia (pest) or perhaps hydroids.

IMHO, if they are aiptasia, because of their proximity to the zoas, your best bet will be a syringe and boiling water directed right at the base

 

[Tcox]

Yes, my apologies. I am referring to thin, white straw-like growths that range from approximately 1/4-1/2 inch