orange sponge?

[ascvet]

I have this orange stuff growing on a rock. It looks like little chains or cirlces lined up in double rows. Any idea what this is?

 

[greenbean36191]

It sounds like a colonial tunicate rather than a sponge. In any event, both are harmless filter feeders.

 

[NanoReefWanabe]

could also be Egg clusters? what do you have in your tank that you know about?