ID please

[DrayB]

Hello guys and gals

was taking some shots of the tank and only noticed these when doing some editing......
tiny little things.....all on one bit of lr but the more i look at that rock...the more i see.
are they tank invaders ???

 

[oldsaint]

Clavularia sp.

 

[DrayB]

good...bad?

 

[ReeferPrime]

There are good but can spread really fast. I think its a tiny waving hand.They are in xenia family so if don't mind them growing fast then they will look really pretty and will be very enjoyable. Good Luck with your tank.