What is this??

[meintn]

This has grown on my temp probe in my sump recently. White and stringy, any ideas??

 

[SpartaReef]

looks like a type of sponge maybe?

 

[meintn]

I wouldn't think it'd be that stringy though. Is growing in another place in the sump too.

 

[Tahoe61]

It is a sponge.

 

[solar]

Aliens. James has some growing in his sump also.

 

[bct15]

It's a sponge, I had some really big pieces of that in my tank at some point.