Something growing in overflow, sponge?

[Ayang90]

Hi everyone,

I had not checked my overflow box in a while so I decided to clean it this weekend. Upon opening I noticed there is a sponge like thing growing on the back. A few copepods scattered when I opened the lid as well. It's brown/tan in color with rather large hole structures.

It's on the lower right in the attached picture.

Any thoughts on what this is? Should I scrape it off?

I have a mixed reef 70G display with a 30G sump.

Thanks in advance.

Alan

 

[Hyde2406]

No idea kind of looks like a sponge