Charcoal black rock

[Treefer32]

So, I never thought anything of this, just thought it natural, but, I've noticed that my larger base rock (which I have laying across two rocks to form a tunnel) and One other rock next to it turning charcoal almost black. It's the same rocks I've had a tough time keeping corals alive on. I had lost a couple months back a large Stylaphora and birdsnest, (they both had gotten quite large when they died). Is there something that would cause rocks to turn charcoal gray / black? There are patches of coraline algae, but it's very small patches. . . These are large 20 lb rocks that have turned gray / black (maybe larger).

 

[Rjmul]

Photo ?

 

[Treefer32]

Photo ?

 

[Rjmul]

I'm no expert by any means, but that looks like sponge growth. Does it look like this

 

[Treefer32]

It's more dotted than that, but yes, looks similar in broader patches. My bottom rocks are covered in yellow sponge, which I don't mind, adds color. There's a such thing as black sponge?

 

[aurora.k]

There's a such thing as black sponge?

Yep, I have lovely black sponges

 

[Bam327]

i would get that rock out asap. Black sponges are nasty killers

 

[Treefer32]

i would get that rock out asap. Black sponges are nasty killers

What do you mean by nasty Killers? More information please? Killers of what? anything they touch or ?

 

[Bam327]

What do you mean by nasty Killers? More information please? Killers of what? anything they touch or ?

I haven't dealt with it personally, but I'm pretty close with my LFS owner and watched him deal with it. He had a nice colony on blasto's on a baseball sized rock (I kept asking about these and he wouldn't sell them to me). The rock had black sponge on it that ended up choking out most of the blasto's. When he went to remove the rock, the sponge had encrusted and attached the rock to the sides and bottom of his tank. He had to use plyers to remove it. If that is indeed black sponge, I would get rid of it.

 

[Bam327]

Here's a post I found re Black sponge from 2004

"This black sponge is pretty aggressive, I had it and it completly surrounded a sunset montipora encrusting SPS. (SPS tend to be pretty aggressive themselves, particularly the encrusting ones). It completly engulfed it and was cresting over it before I decided to take action. I watched it closely for chemical warfare, and the sunset looked destined to lose. I let it grow for about a year and probably covered 6 square inches at least.

This sponge seems benign and of course we have all heard sponges are a "good" thing, but after having this one, it is very resilient, tough to get rid of and looks like it can overrun a tank in time....covering your LR and anything else in the way.

Get it out!!! If you can, I would ditch the rock it is on, or at least take it out and try it out and kill it, then later on after its all cooked out, put it back in later on.....trust me its worth it to over react and get rid of it.

Covering it up with a layer of putty should do the job, but expect a spike from the die off, so play a decient WC when you do it.....that would be the easiest I suppose, but it grow equally well on both light and dark sides......"

 

[Treefer32]

Here's a post I found re Black sponge from 2004

"This black sponge is pretty aggressive, I had it and it completly surrounded a sunset montipora encrusting SPS. (SPS tend to be pretty aggressive themselves, particularly the encrusting ones). It completly engulfed it and was cresting over it before I decided to take action. I watched it closely for chemical warfare, and the sunset looked destined to lose. I let it grow for about a year and probably covered 6 square inches at least.

This sponge seems benign and of course we have all heard sponges are a "good" thing, but after having this one, it is very resilient, tough to get rid of and looks like it can overrun a tank in time....covering your LR and anything else in the way.

Get it out!!! If you can, I would ditch the rock it is on, or at least take it out and try it out and kill it, then later on after its all cooked out, put it back in later on.....trust me its worth it to over react and get rid of it.

Covering it up with a layer of putty should do the job, but expect a spike from the die off, so play a decient WC when you do it.....that would be the easiest I suppose, but it grow equally well on both light and dark sides......"

Right now, it's not looking fleshy like typical sponge, it's more like black film algae. Sponge I think of as being thick and puffy. This is encrusting on the rock almost like a black coraline algae, but, I haven't tried scraping it to see if it's sponge or film algae, or coraline algae. ugg. I was thinking of taking a rock without any corals out and just scraping it in water wchange water to see what comes off and what is fully encrusted.