How bad is this going to be?

[jimk60]

I have these tiny polyps popping up in various places. Start out looking like some sort green algae then blossom into a green or white polyp about a quarter inch in diameter. I'm afraid they might begin taking over. Has anyone seen these before and

how did it turn out.

 

[easternreefer]

helps to read.. look up clove polyps or colonial hydroids