What are these white growths?

[DraggingTail]

Would anyone know what these white growths are under the milli on the rock?

I notice these popping up everywhere on the rock.

I originally thought there were snail poop but they don't scrub off.

 

[James M]

Look up spiroid worms

 

[Flippers4pups]

Agreed. Not a problem unless they become plague proportions for pumps....etc.

 

[Flippers4pups]

All over my sump, not a problem for me.

 

[DraggingTail]

Does that indicate a healthy marine ecosystem?