fuzzy stuff growing on live rock

[brian91]

got these fuzzy white things grown off live rock anyone have a clue what it is and is so is it bad or good?

 

[Turbosnail]

Looks like hydroids I would get rid of them the tend to irritate corals.

 

[brian91]

is there a way to get rid of them

 

[willray]

Kalk paste them! Twice! Say 3-4 days apart.