What is this??

[Dtfnemo]

Hi guys, I just notice some thick patches of what looks like coraline??
Is it coraline or is it something I should be worried about?
It looks thicker that the coraline I have all over the tank, it has some texture to it.
It's growing on different places of the tank.
Anyone experience this before? Is it good or bad?


Bottom of the rock

 

[ReeferMaddness843]

Looks to be a sponge. Harmless filter feeder. Sign of good chemistry

 

[Dtfnemo]

Good chemistry?! Oh yeah I'm getting good at this

 

[Dtfnemo]

Looks to be a sponge. Harmless filter feeder. Sign of good chemistry

Thank You! Didn't know they came in that color