ID on mystery growth

[florenceSC.nanoreef]

Please help me id if this is good or bad

 

[pugcrush]

Looks like sponges. It's a good thing - a sign of system maturing.

 

[florenceSC.nanoreef]

It's the white stuff, it looks almost the stuff that grows on the underside of a fallen rotten log.

 

[Salty1962]

Yes, those are sponges. Harmless unless they get out of control.

 

[florenceSC.nanoreef]

Ok thank you