Any idea what these are?

[Seadoc]

Hi all. Found these in one of my frags. Give that the frag has been in the system
for a while I am assuming I have these everywhere. Assuming more a nuisance than anything else but would appreciate a confirmation.

 

[sfin52]

Vermetid snail

 

[ScottR]

Common detritus worms.

 

[Vette67]

Those don’t have the coiled bottom of a vermetid. Those look like colonial hydroids. They are harmless, but some people think they are a nuisance, because they can grow like crazy. So, personal choice if you want to get rid of them or not. I have them on rocks in my refugium, and I like them, so I’m letting them be.

 

[Seadoc]

Thank you all for the help. Much appreciated

 

[vetteguy53081]

Filter feeders and simply prevent them from getting to food and allow to starve. If not, will become a colony