Is this a sponge?

[Dipi]

Hello guys,

I just noticed this on my rock. It is porous but I'm new to.reefing and can't be sure if this is a sponge or some kind of mold or other critter. Should I remove it?

 

[ryanjohn1]

Looks like a sponge. Kinda hard to tell in picture

 

[Reefing102]

Best I can tell it’s a sponge as well

 

[Dipi]

Thanks! I will let it be then and keep monitoring

 

[Pascalereefer]

Hello, curious if this is the same as what you're seeing? It's about the size of a quarter, a bit smaller, and is in a shaded area

 

[Dipi]

Hello! I think it is, definetly looks the same. I have zoas happily growing on top of it, so it is probably not harmfull