Good sponge, bad sponge?

[ReeferTCG]

Hi all, just a quick ID. This is growing under my wall hammer

 

[tzabor10]

I was not aware sponges could be bad.

 

[exnisstech]

Love me some sponges. I think I've only read about a type of invasive sponge once. I see sponges as a sign of a healthy maturing tank. I have sponges all over the rocks in shaded areas.
This is the rock my 10yo bubble coral is on. Its like its own little eco system.

 

[Subsea]

I like sponges as well. While the cryptic ones don’t look especially cool, I know that they are enhancing water parameters thru their biofiltration.

Cryptic sponges consume DOC & POC. and they produce DIC and energy rich detritus that feeds the microbial loop. Dutch researches documented that cryptic sponges would double in density every 2 hours from weight of particulates absorbed except for detritus produced.

PS: pictures would be better if glass was clean. I am retired, I will clean it when it moves me.