White stuff on media ball

[HumbleAsianReefer]

Hello guys. Anyone can tell me what this thing is?
8-9 months tank. But this media ball is transfered from my previous tank, age around 4years++ if not mistaken. I noticed this just a few days ago. Is it friend or foe? Thanks

 

[ISpeakForTheSeas]

Feather duster worms tubes, and possibly a pineapple sponge - harmless filter feeders.

 

[HumbleAsianReefer]

Feather duster worms tubes, and possibly a pineapple sponge - harmless filter feeders.

Ahhh okay. Thanksss