Can anyone I'd this?

[moseley75]

It was on the live rock I purchased with my new BioCube. It is growing rapidly and spreading. Is it good or bad?

Thanks for any help.

 

[Charlesbrooks]

Good,... It's a type of Forminiferans = (Homotema rubin)

 

[AllSignsPointToFish]

I agree they are harmless. I would think it's a marine sponge similar to Plakortis.