What is this white thing ?

[SInMontreal]

Hey guys! I'm not sure what is this white thing. Can anyone tell me is it bad or harmless? It started appearing on my rock and glass and frag plug.

Thank you,

 

[JasonK84]

Vermetid snails

Some say they irritate corals.

 

[cmcoker]

I'd say probably spirobid worms..
http://www.melevsreef.com/critter/spirorbid-worms

 

[KJ]

Spirobid worms.

 

[Lovemyreef2015]

Agree spirobid worms. Harmless

 

[SInMontreal]

Thank god it’s harmless. I was worried ab it. Thank you guys so much

 

[KJ]

Thank god it’s harmless. I was worried ab it. Thank you guys so much

YW