Tube worm, feather duster or Satans spawn?

[BubblesandSqueak]

So during today’s water change, I moved some sand back and found these. Are these pure evil or some sort of feather duster? Would have come in on a coral at some point.

Funny I was thinking about getting a FD at some point but thought my flow was too strong.

 

[Crabs McJones]

look like fan worms to me. cool find!

 

[BubblesandSqueak]

I've got like a dozen of them which Is why I'm concerned. I'll try and blow some more of the sand away. The jawfish has been piling sand there.

 

[kevgib67]

Good filter feeders!

 

[BubblesandSqueak]

Good filter feeders!

funny seeing a little colony of them and not just a loner. wouldn't have expected this as a hitch hiker to coral frags.

 

[addictswife]

I have these also. And they are spreading. I know they are supposed to be good but it seems like they are spreading like weeds. Not sure that I like that.