Aipitasia or Sponge

[RMC]

Have this stuff growing on my live rocks (mostly in low light areas), after some research I'm still struggling with the ID. Narrowed down to some sort of Aiptasia or sponge. Also, trying to get rid of it, any suggestions appreciated!

[spit.fire]

Sponge

[monocus]

it's cryptic sponge.keep it as it filters your water

[SeaHorse_Fanatic]

Yup, I love it when my rocks grow sponges. Most efficient filter feeders.

[RMC]

The Verdict is in. The sponge stays!!

Thanks for everyone's help