Unsure of what these are

[weirdedout]

We noticed these white things a couple days ago. Kinda looks like a white polyp type of thing but we're not sure. Anyone know what these are? They're the very tine white things attached to the rocks.

 

[Rob&Gab]

Looks like hydriods but I could be wrong.

 

[jcdeng]

Yes those are hydriods, some fish will pick at them, can sting corals, but usually go away on its own as tank matures.