Feather Duster, Tube worm, or Aptasia?

The sump under my 75 is full of them. They have white crowns, banded crowns, pinkish crowns... so crown color or pattern isn't going to help ID the spp.
Just looking at the pic and guesstimatig scale and where it's chosen a home I'm positive it's a micro duster. It may get a little bigger. The largest I've ever seen in any of my systems grew a crown about the diameter of a quarter.

 

it's got really cool coloration. Nice find!

 

Thanks again for all the good info!

Good ol 3Reef!

I may move the mushroom that is trying to cover it's stalk.

 

Argh, the nasty worm hitchhiker page. Some disgusting stuff on there!

+whatever on the feather duster. Thought I had only one just found a second one. Good filter feeder.

 

I've never seen them bigger than a quarter either. I think other guy might be getting them confused with other feather dusters.