Pin Cushion and Fan worms

[H0nda42]

Hi all, I have a nice yellow pin cushion which has been thriving in my tank for the last 3 months. However in the last 6 weeks I am having more and more fan worms coming up everywhere. They are growing on 1 or 2 rocks specifically and have now covered the base rock of my pin cushion. I have left it; but on inspection last night I noticed that the pin cushion's flesh was a little eroded where the fan worms has grown. I scrubbed them off last night (pin cushion obviously not happy about that) but I am sure they are just going to grow back.
Is this serious? Can they cause damage to the pin cushion should I keep scrubbing them off or just leave them.

Any help will be greatly appreciated.
THanks,

 

[Warr7207]

Nope, won't harm the pin cushion. Have had similar situation.

Fan worms are good at growing anywhere.

I have them growing in my skimmer, carbon reactor, PO4 reactor and on my macro algae.