Found n Refugium - Need help to ID this foamy/sponge thing

[KenBabich]

Hi all!
I have an AquaMaxx HOB refugium on a Waterbox AIO 50.3 (4 months old) - no chaeto, more of an algae scrubber at this point. When I do maintenance these white semisolid foamy/sponge like items are found in the algae or located solo. Most are all white, with some having a yellow/rust/brown stain like in the photo. I occasionally find pineapple sponge in the tank, and these refugium items don't resemble them. Largest one was almost 2 inches. No foul odors, refugium flow not vigorous but circulating, algae grows thick and green. Is this a sponge? Congealed proteins and fats? Thanks!

 

[MoshJosh]

my guess is. . . sponge. There are tons of different types and it's possible that these specific ones prefer the conditions in the fuge (flow, light, etc) and that's why you don't see them in your tank.