Black sponge REEF2REEF Saltwater and Reef Aquarium Forum

I've been told this is black sponge. Do I remove it? Will it spread?

Pest Sponge REEF2REEF Saltwater and Reef Aquarium Forum

What is this. A sponge hitchhiker???

Brown stuff (maybe algae) on my sea sponge.

Black Encrusting sponge ID REEF2REEF Saltwater and Reef Aquarium

Experts-What is this black stuff?

Strange sponge(?) breeding REEF2REEF Saltwater and Reef Aquarium

Sponge ID? REEF2REEF Saltwater and Reef Aquarium Forum

Black sponge? REEF2REEF Saltwater and Reef Aquarium Forum

Encrusting black sponge REEF2REEF Saltwater and Reef Aquarium Forum

Is this a sponge of some sort? I haven't added anything to my tank

Purple slimy sponge rock REEF2REEF Saltwater and Reef Aquarium Forum

Disease and treatment? REEF2REEF Saltwater and Reef Aquarium Forum

What is this thing??? Help a noob.