ID please. Good or bad. Help

[Arrecife]

Hi fellow reefers.

Tank is a 90 gallon mix reef. 3 years old.

See pictures ( this little fan looking things are everwhere, seems to me they have a calcium body of some sort ) I want to know what they are and their function in the tank, kill methods if is bad or appreciation if is good.

Thanks for the help

 

[dvgyfresh]

Fan worm , harmless filter feeders , nice hitch hikers

 

[Doctorgori]

been years since I’ve seen those…stash some in the sump as many fish will make quick work of those…. I’ve personally been looking…thought those went extinct from the hobby

BTW those can sorta get outta hand…no real harm however

 

[dvgyfresh]

been years since I’ve seen those…stash some in the sump as many fish will make quick work of those…. I’ve personally been looking…thought those went extinct from the hobby

BTW those can sorta get outta hand…no real harm however

Petcos saltwater rocks are usually covered in them ime

 

[markwayts]

Hi fellow reefers.

Tank is a 90 gallon mix reef. 3 years old.

See pictures ( this little fan looking things are everwhere, seems to me they have a calcium body of some sort ) I want to know what they are and their function in the tank, kill methods if is bad or appreciation if is good.

Thanks for the help

Fan worms. Harmless to helpfull.
Not to be mistaken with tube snail. Tube snails cast a slime web instead of having a fan.