Help me identify these things in my media chamber

[oki2oki]

Hi
In my media chamber I noticed these white things today. My tank is 4 months old. Can someone tell me what these small white dots are and what these bigger things are and should I be concerned?
I have few anemones with clownfish and few blue leg hermit crabs.
Any help and comments would be greatly appreciated.

Thanks A

 

[ying yang]

Spiribid worms and pineapple sponges
Edit:Both filter feeders and no harm unless reach plague proportions and can apparently clog up pipes impeding the flow ( what I read others say but no real experience of it)https://www.reef2reef.com/threads/what-is-that-a-r2r-guide-to-common-new-tank-hitchhikers.443382/

Some more common hitch hikers you may encounter and bit if info on above 2

 

[Eagle_Steve]

Spiribid worms and pineapple sponges

Second what @ying yang said.

 

[Gqch]

dont know their names but as i know they are filter feeder as sponge and feather duster, they are good for reef tank.

 

[oki2oki]

Thank you all!