HELP! White Jelly-like worms taking over sump and refugium.

[captpetefl]

What is this infestation? It’s contained in my sump and especially my refugium for now, but I’m afraid my display is next.
I assumed flatworms, but they just look a bit different than the pics I saw online. They are also fairly firm/hard and do not squirm or move when touched.

ID anyone?
Good or bad?
Defense/treatment?

 

[bradleym]

These appear to be a type of sponge. They are not harmful, and will likely avoid growing in high light areas.

 

[Troylee]

Agreed! The white is a sponge and the reddish brown look like planira flat worms.

 

[ISpeakForTheSeas]

Yeah, looks like sponges and most likely flatworms to me.

 

[Reefkeepers Archive]

The whites are sponge. Completely harmless, mine went away in a few weeks. The reddish-brown might be flatworms but idk, definitely trust @ISpeakForTheSeas on that one

 

[8-Bit Reefer]

sponges are a sign of a good maturing tank!