Pest or not?

[Jonno411]

Is anyone able to identify this? Not sure if it’s a pest or not and would like to get on top of it, if it is. Tank was recently moved to a new home, basically everything except the sand was kept in the move. It appears to be growing on parts of the rock that were previously under other parts of the rock.

 

[SlugSnorter]

harmless "feather duster"

 

[dakoop]

Agree

 

[Bucs20fan]

+1 Feather duster, safe harmless and as always pretty cool.