Bleach cure dried live rock

[Randy Holmes-Farley Verified Community Expert]

Vinegar is about 5% acetic acid.

I think you have to play this by ear. Pour some on the black surface. Does it bubble? Does the surface look whiter? If nothing happens soak it go overnight.m

Judging from the pics, it may be hard to distinguish bubbling from the dissolution of the black material from bubbling from dissolution of the rock under and around it.

 

[KrisReef]

It is possible the black is metal sulfides. Removing it seems prudent to me.

Interesting.

Would you recommend testing for copper or? Metals?

 

[KrisReef]

Ok so I did a SUPER long bleach cure. Forgot about the bucket for several months. It was dried live rock. The rock in question I believe was from Jakarta. It had a lot of organics on it. After the long bleach cure I saw some black stuff on the rock, maybe was there before. So I did another bleach cure a couple times, more correct timeframe. Black is still on the rock. It is smooth and does not scrub off. Almost like black coralline. Other ricks in the same container did not have this happen. Couldn’t be mold right lol?

I think the fact that the black is in crevasses makes me think of anoxia and sulfides as a opposed to dissolved rubber fragments.

I might test for copper, ( not because I know it is there but to rule out that it is.

But I don’t know what the stuff is and so I am just trying to minimize risk from what I might be looking at.

An ICP from a soaking bin might be helpful?

 

[Randy Holmes-Farley Verified Community Expert]

I probably wouldn't bother metal testing. The metal sulfides likely to be present, such as iron or copper, are quite low solubility.

 

[reefer10]

I’m not sure what metal it could be other than the magnet from the power head. This was in 1/10 ratio bleach rodi water for a few months. There was a lid on the bucket also. The rock was dry live rock from Jakarta in large bins from a store. Almost positive never in a tank.

 

[reefer10]

I think the fact that the black is in crevasses makes me think of anoxia and sulfides as a opposed to dissolved rubber fragments.

I might test for copper, ( not because I know it is there but to rule out that it is.

But I don’t know what the stuff is and so I am just trying to minimize risk from what I might be looking at.

An ICP from a soaking bin might be helpful?

What do you mean by anoxia and sulfides? Lack of oxygen pushed sulfides into crevices?

 

[Randy Holmes-Farley Verified Community Expert]

What do you mean by anoxia and sulfides? Lack of oxygen pushed sulfides into crevices?

Low oxygen regions allow organisms to use sulfate instead of oxygen, and that produces sulfide. The sulfide produced reacts with metals already in the water to deposit metal sulfides, such as iron sulfide.

That said, I am not sure that is what the black stuff is.

 

[reefer10]

It couldn’t be anything from the magnet could it? It was 0 tds ro di water so should have no metals?

 

[Randy Holmes-Farley Verified Community Expert]

It couldn’t be anything from the magnet could it? It was 0 tds ro di water so should have no metals?

I don’t know, but the rock will bring in its own metals inside of the organic matter you were bleaching.