What is this stuff???

I had a clump of coral that was in the tank. I asked the PO what it was. He didn't name it but said it was one of the first he bought.

Well, it was just a clump of stuff. Covered with algae. No discernible anything. So... I got rid of it. Well, where ever it attached itself to rock it is still there. Thought it would just dissolve and go away, but it seems to be growing. It just looks like calcirous growth. What is it?


The greyish growth with the hole. Three of them.



The stuff below the bubble algae.

 

Hard to tell from the pics but looks like sponges possibly

 

+2...my first reaction was sponge.

 

I thought sponge was somewhat non standard. I thought he bought coral.

Just got back from the LFS, and he had some of the same type stuff growing. Sponge. He said get rid of it. I'm inclined to do just that.

Do I just scrape it off. What eats sponge? I thought my tangs would eat it.

 

Why would you scrape it off, they are great filter feeders and some get really pretty as they get bigger. Never heard of a fish eating sponges. But if you must remove it just scrape it off.

 

Yep, looks like sponges to me..

 

That is definately a sponge. All angels eat sponge but most will also eat corals too. Same goes for Moorish Idols. The sponge is not going to hurt anything so why not just leave it?

 

When I moved the tank, I had to take all the LR out. So when I set it back up, obviously it was not the same. I have about 5 or 6 rocks with it on it. The LFS said they will just cover all the rocks. For right now, there is no real reason to remove them. I will let them grow since I have room. Hopefully they will not become a nuisance.

 

If it was a black smooth sponge, I would say get rid of it. That's a very aggressive species. However, this one is harmless.