Help ID algea or bacteria

[Lui1521]

Help ID this algea and how to get rid of it if I need to!

 

[Lovemyreef2015]

They look like green star polyps coral. They do grow like weeds. We have them in our reef.
Edit: just keep them isolated to one rock or they can quickly take over a tank. They are pretty and we enjoy them in our tank.

 

[Lui1521]

They look like green star polyps coral. They do grow like weeds. We have them in our reef.
Edit: just keep them isolated to one rock or they can quickly take over a tank. They are pretty and we enjoy them in our tank.

Yes it’s on my GSP but there’s and brown thing growing on its purple mat. It’s on an isolated rock and I’m not sure if I have to remove the rock and remove the brown thing or bad enough that I need to coral dip it

 

[Lovemyreef2015]

Oh lol, I didn't see that at first. Can you take a picture with whites on?

 

[Lui1521]

The gsps open now so it’s hiding under them but you’ll still see the white part of it.

 

[Lovemyreef2015]

Possible sponge or detritus build up. When the polyps close try gently brushing it off with a soft toothbrush.