Mass found growing in sump

[buckeye]

There were smaller chunks, this was by far the largest. There are tiny white sections attached to walls of sump elsewhere. This large area was at the back where tank drains into sump(the area that never gets cleaned). Ive been getting little specs of something in my display, look almost like microbubbles is what started the search

 

[exnisstech]

Looks like the white sponge I get. I get black ones as well but in darker areas like the bottom of rocks. Harmless and maybe even a little helpful I believe.