ID help.

[oconn21]

just noticed this clean fan like thing today decent size. coral had been in tank about 2 months. Added other coral 2 weeks ago from WWC and dipped them

 

[redfishbluefish]

Appears to be an aiptasia anemone.....a pest anemone.

 

[vetteguy53081]

It is aptasia as just mentioned. Simply take a syringe and inject either lemon juice or preferred, kalkwasser powder mixed into a paste the consistency of toothpaste and inject into center core of aptasia and it will melt away.

 

[rockdiver]

I would do what they said BUT in a bucket quickly