Aptasia, tube worm, or something else?

[BIGSKY71]

What are these guys. They seem to be multiplying but not getting any bigger. They are pretty small. These have been here quite a few months. There is also a bristle worm (have LOTS of those)
Thanks

 

[thereefhotspot]

What are these guys. They seem to be multiplying but not getting any bigger. They are pretty small. These have been here quite a few months. There is also a bristle worm (have LOTS of those)
Thanks

Not Aptasia. Looks to me like a species of hydroids. Arrow crabs can help you take care of the small bristle worm. You’ll still want to remove big bristleworms as you see them.

 

[Alexraptor]

Small featherdusters, harmless filter feeders. They tend to thrive in systems with a lot of particulates floating around. Food, detritus, etc.