can soneme tell me what the hell it is?

[rafaelpty20]

This stuff grows real slow, and it kill my green star polyp. I try to brushed off but, i dont want this to start showing everywhere in the tank.

 

[ca1ore]

Sponge

 

[Cheje]

I have sponges growing on my GSP without any problems. Doubt it would cause any harm.

 

[Bogue Chitto]

Yep, sponge.

 

[jchassie6312]

I have these all over my tank. Harmless.

 

[Ron Reefman]

This stuff grows real slow, and it kill my green star polyp. I try to brushed off but, i dont want this to start showing everywhere in the tank.
[/URL]

It's a sponge and it's not very likely that it killed your GSP. More likely that something else is wrong in your tank. The GSP would grow right over the sponge.

 

[Sapelo]

^^ What Ron said.