blue-black layer??

[maleks.reef]

Hello everyone. Currently, I am in the process of bleach curing my (old) live rocks. As you can see in the picture attached below, one of the rocks has this weird blue/black layer on it that is similar to coraline alga. I thought the bleach bath would remove it but no it didn't, the rocks have been in this 10:1 (Ltrs) water to bleach mixture for 9 days now and it is not going away.
Does anyone know what it is?? And is this rock even usable or should I throw it away?

Tha

nks.

 

[maleks.reef]

#reefsquad

 

[Ron Reefman]

I have some flat 'shelf' type rocks that look just like yours. I got them from a reefer getting out of the hobby. I used a couple in my last rockscape and they appear to have been harmless.

That said, I have no idea why they have that color or what the maker used to make it that way.

Good luck. I'm following just in case somebody can shed some light on the issue.

 

[maleks.reef]

I have some flat 'shelf' type rocks that look just like yours. I got them from a reefer getting out of the hobby. I used a couple in my last rockscape and they appear to have been harmless.

That said, I have no idea why they have that color or what the maker used to make it that way.

Good luck. I'm following just in case somebody can shed some light on the issue.

I got these rocks from someone getting out of the hobby as well. I have been curing the rocks in a bleach water mixturefor nearly 2 weeks now in an attempt to minimize the nitrates and phosphates that might be in the rocks. But I am afraid this blue stuff might be something very bad for my tank. Do you think it could be cyano bacteria?

 

[Ron Reefman]

No. I don't think so. I think it's either a dye they added to color the rock when they made it. Or it's something in the materials they used. But I've had some of it in my tank for a year and it has not been a problem. It doesn't seem to be leaching anything.

 

[maleks.reef]

No. I don't think so. I think it's either a dye they added to color the rock when they made it. Or it's something in the materials they used. But I've had some of it in my tank for a year and it has not been a problem. It doesn't seem to be leaching anything.

You have a rock with some blue-black stuff on it as well?

 

[Ron Reefman]

You have a rock with some blue-black stuff on it as well?

I have several, and one good size one has been in my 90g tank for the past year. The others have been in a Brute full of saltwater and a pump, along with a lot of other rock. Over the next few days I'll be doing a new rockscape and documenting it in my build thread.

 

[maleks.reef]

I have several, and one good size one has been in my 90g tank for the past year. The others have been in a Brute full of saltwater and a pump, along with a lot of other rock. Over the next few days I'll be doing a new rockscape and documenting it in my build thread.

And so far they have not affected ur tank in any way correct?

And good luck with your new scape!

 

[Ron Reefman]

I just uncovered part of that rock and it has zoas growing on it. Tomorrow, when I pull it out I'll take a photo. I've had no issues with it.

 

[SHNICI]

I just uncovered part of that rock and it has zoas growing on it. Tomorrow, when I pull it out I'll take a photo. I've had no issues with it.

Ron, I think, that's caused by the NItrosomonas bacterias. I have aragonite gravel in a glass jar (0.5-1mm grain) , this one on the bottom is all the gravel the same as the LR. when I stirr it a bit and turn the blue colored to come on the top, after month or more the top layer is coming wite again, and all the blue/black coloration/pigment is moving at the bottom layer.
I try year ago second jar like this to bleach the gravel and to use it, after I left it in the bleach for near 1 week (undelutet solution) the gravel remain the same color and after I put it in the jar (like the other one, I had 2 glass jars with gravel and water to the top).
Hope you understand what I mean. But why the bacterias change the color of the surface, no idea.

 

[Dr. Jim]

I've seen black material on large rock that I split open. I assumed it was some form of deposit (sulfates?) from anaerobic bacteria. Maybe that piece of rock was buried deep in a sandbed??

 

[SHNICI]

That's just now, I have this since 2018 (it's closed completely (watertight)
When (if) I put it on daylight the side which is to the light is coming normal the inner s darkening.
Also at the Beginning when I seti it up (mid 2018), I just put in aragonite gravel in and the water come from my tank during cycle with BA MicroBacter7 and 4 different brands for fast cycle and that happen literally for about a week. Say the water in was overpopulate with bacterias all different strains.
Now when I have to run new tank (I done it on experiment with 20g tank), it finish the cycle for about week and half - 2 adding from the gravel only from that jar (about 1 teacup and I took and place properly all the lears as they are in the jar)