featherduster

Hello all! During a sand bed cleaning I just bumped my trachyphyllia that I've had for about 2 months. It looks like there is a feather duster worm hitchhiking on the bottom. Is this a feather duster worm and it's harmless? Or is it something else? Should I remove it? If so, how? Thanks in advance!

idk how I got these tiny feather duster guys in the first place but they are getting completely out of control. I really don’t mind them on my rockwork but they are completely covering my eagle eye zoa. I’ve tried picking at them and brushing them off with no luck.. I heard from my lfs that a...