Something Odd in Sump

Hello All,

In the attached picture, you should be able to see something odd growing out of a activated carbon bag that I have in my sump. I am in the process of cleaning out my sump. I have noticed new white sponges in my rocks and in dark, nutrient rich areas of my sump. This is new to me. Is it a sponge? Aptasia maybe?

Bad, good? Neutral? It should be easy for me to remove.

Thanks.

Attached Thumbnails