Weird white strings in my pump?

[Bigtex817]

can anyone please tell me what this might be. I was cleaning my return pump and noticed this white stringy stuff. Pic is attached.

 

[Jeepguy242]

Are they soft or encrusted.

I get encrusted tube worms on mine that look similar

 

[Bigtex817]

I don’t know didn’t want to touch them. When I ran hot water over them some came right off and others I was able to use a toothbrush to scrub off with not a lot of pressure.

 

[Jeepguy242]

Probly tube or spegetti worms

Harmless filter feeders