Help! Is this fungal or sponge?

[Everardo_farias]

I need help identifying if this is a fungal infection or just sponge growing? Torch is doing okay and haven’t seen much growth in over a year. I have tried brush it off but it grows back a month later.

 

[Spare time]

Sponge or tunicate.

 

[WheatToast]

Sponge. I have a similar one that hasn't harmed anything:

Tan sponge: