Long Established Reef Rock Turning Black

[radiata]

No, but I did run my finger tip over it to see if it could be wiped off. What I can say is that it does not appear to be growing on top of the rock, it seems to be a pigment change in the rock itself. It feels no different than the coralline algae growing next to it. I placed the small broken piece, from my pics above, back into the reef. I will try to brush it off when I have a chance. Thanks for the suggestion.

Hmmm... Maybe you've discovered a new coralline color morph. I once opened a 5g bucket of live rock that I sealed up many years before and had forgotten about. I found coralline colors that were quite new to me - both orange and green. The bucket was a little translucent, and was not completely in the dark. The new colors quickly disappeared - they had developed in an anoxic environment and didn't last long once exposed to fresh air.

 

[Nano sapiens]

@Nano sapiens
hey you gotta admit its rare to see absolute proof up close of something so old. visual benthic indicators/off the charts. cross sectioning/layering, info gold regarding tank aging OTS etc, this is puzzle piece rare. the sponge is a hassle but Id get serious about spot peroxide work, and rasping, and see if it can be burned out. at least try to knife tip rasp that stuff off a rock as fully as you can, then peroxide the clean areas avoiding the pristine coralline, let bake a sec, rinse put back and try and guide out

his OTS manifestation is a rascal hitchhiker. no different than someones bryopsis after 27 years...this one manifests as a wraith but its not a bacterial imbalance I bet as Ive never seen marine versions of that pigmented anything but whites/cream/browns and purples but all black I vote sponge unidentified what do you think.

if he just ridded the invader that rock sails for another millennia. I feel like we're shooting the mare here before we even attempt to build her a robot leg. theres always something to hand guide in reefing, since we present .000000103% of the total macro and micro competitive grazer complement in our homogenized reef tanks.

Hmmm, in this case since there is no sulfur smell, it might be some type of anoxic bacteria or possibly a mold or a fungus. Good suggestions were made to increase flow/oxygen in the tank to increase aerobic conditions and keep blowing off detritus every few days and vacuuming the crud out with your water changes.

Since the OP mentioned hair algae and diatoms (which may be misidentified and actually a type of dinoflagellate...or possibly a combination of both), these organisms thrive when either nutrients are elevated and/or there were some major changes/disturbances to the system.

I currently have 20+ year old ocean live rock in my small reef tank and it shows no signs of deterioration. While it isn't 30+ years old yet, I suspect that it will still be in good shape when that time comes. I haven't seen any studies that show that live rock has a 'shelf life' per se, but I believe that in a lower nutrient and well maintained reef tank it's 'life' is virtually indefinite.

A web search turned up very similar conditions on different sites:

http://www.reefcentral.com/forums/showthread.php?t=2060943

http://www.ultimatereef.net/threads/live-rock-turning-black.684037/

 

[SnakeCharmer]

Hmmm... Maybe you've discovered a new coralline color morph. I once opened a 5g bucket of live rock that I sealed up many years before and had forgotten about. I found coralline colors that were quite new to me - both orange and green. The bucket was a little translucent, and was not completely in the dark. The new colors quickly disappeared - they had developed in an anoxic environment and didn't last long once exposed to fresh air.

I doubt this is the case because every patch of slowly growing patch of black has a ring of bleached out area between it and the healthy coralline.

 

[o2manyfish]

I have live rock that is 30+ years old as well. Having been in this hobby a long long time, and at one point being one of the largest importers of Tonga and Marshall Live Rock (Back in the day). I have seen these black areas that are all the way through the rock in freshly harvested still damp live rock. I've built some large systems using literal tons of giant size live rock (pieces over 30" and over 100lbs) and we had to sledge the pieces to get them to fit and lock. We would find these black bands through the rock. After setting up the tanks, there was never an issue with 'black spot' live rock. And I've never had an installation where the black areas spread as rapidly as you are describing. I have never been a believer of OTS. I mean if coral based rock and sand is millions of years old when collected then 5-20 years (OTS thought to occur) is less than a drop in the bucket of time.

 

[SnakeCharmer]

Hmmm, in this case since there is no sulfur smell, it might be some type of anoxic bacteria or possibly a mold or a fungus. Good suggestions were made to increase flow/oxygen in the tank to increase aerobic conditions and keep blowing off detritus every few days and vacuuming the crud out with your water changes.

Since the OP mentioned hair algae and diatoms (which may be misidentified and actually a type of dinoflagellate...or possibly a combination of both), these organisms thrive when either nutrients are elevated and/or there were some major changes/disturbances to the system.

I currently have 20+ year old ocean live rock in my small reef tank and it shows no signs of deterioration. While it isn't 30+ years old yet, I suspect that it will still be in good shape when that time comes. I haven't seen any studies that show that live rock has a 'shelf life' per se, but I believe that in a lower nutrient and well maintained reef tank it's 'life' is virtually indefinite.

A web search turned up very similar conditions on different sites:

http://www.reefcentral.com/forums/showthread.php?t=2060943

http://www.ultimatereef.net/threads/live-rock-turning-black.684037/

What I am referring to as "hair algae" is green at the base where it is connected but as the filaments grow, they become golden-green and are easily broken free. The base material is well connected. Tangs and other algae eaters will not touch this stuff. I have tried to use them many times.

With use of the term "diatoms", I am referring to the small round brown dots that form on the glass that slowly grow larger and larger. They are not easy to remove and a scraper is the most effective means for removal.

I will take a few pics of the hair algae to share here on Monday.

 

[SnakeCharmer]

I have carefully blown the live rock out twice now with a small pump. I was able to remove quite a bit of solids and I believe that the live rock can breathe a bit better now. The corals look the same (doing fine for the most part) and I did notice less algae growth on the glass.

The "mold" is still spreading, although a few areas are fading to grey. The Yellow Polyps that are colonized on one of the rocks that is turning black are clearly distressed by the black patches, as they are shrinking where they are attached to the black areas but healthy on neighboring coralline covered areas of the same rock.

I attempted to vigorously brush it off with a firm bristled plastic brush. No effect at all. It is just like coralline algae in texture and toughness.

Something interesting to note. The black patches only grow where light reaches the rock. There is none at all on the undersides. I have the rock arranged to create small caverns throughout. The undersides are covered by healthy coralline and some sponges. Perhaps the black patches are photosynthetic? IME, mold is not photosynthetic.

I have not yet tried to apply peroxide to an affected area but I feel that it would likely fade/kill/remove it from the surface of the rock. To remove every infected rock would have me basically disassembling the reef which would probably be disastrous, so I would like to avoid doing that at all costs.

Your input would be appreciated. Thanks.

 

[BluewaterLa]

Live rock does not have a shelf life by any means.
Can we do things to make it less desirable ? Yes of course and neglected rock can be a bit unhealthy but not bad thats not the way bacteria work.
Your Live rock if broken apart into rubble will reveal all sorts of deposits trapped within from many years of formation.
sometimes rock can get different color forms ''growing '' out of the rock or on the surface due to Bacteria populations, other microbial life and from the sea water reacting to the many deposits within the rocks layers.
Changes in Aquarium water can trigger die off events Or growth events of living organisms just as well can expose layers of rock previously not seen due to the coverage of coralline algae.
Years back we had an abundance of live rock available to us for use in this wonderful hobby. Just like a person has mentioned the black bands on and inside some of the rock we have seen patches of rusty looking orange, dark maroons, Blue, Black, yellow yada yada yada..... on and within the rock.
This is most likely coloration of the rock that has always been there or just below the surface a change in lighting or chemistry can cause coralline algae to die off exposing the rock to light for the first time in a long time so no telling what is under that pretty purple.

I once had two 180 gallon tanks plumbed into one system in which both were holding massive sized live rocks ranging from 30 to 80 pounds each.
Some of this rock had multiple dark to black spots while some had other colors of the rainbow, all to which did not bother anything.
Over time some of the spots were covered up with new growth of coralline algae and some covered by sponge and or feather dusters.
There is a soft to the touch dark purple coralline algae that only comes in on real reef live rock that I used to have lots of years back, most of it was either killed off by a power outage from a hurricane or got smothered out by the faster growing pink variety.
One small rock in my current tank still has a healthy complete coverage of this coralline and it prefers lower light or it bleaches out.
Usually when it gets covered up / smothered out or dies off is when I see spots like you pictured being exposed.
may have more to do with your coralline dying off in that particular area in my opinion.
Have you changed anything with your lighting or chemistry in the past few months ?

 

[SnakeCharmer]

Live rock does not have a shelf life by any means.
Can we do things to make it less desirable ? Yes of course and neglected rock can be a bit unhealthy but not bad thats not the way bacteria work.
Your Live rock if broken apart into rubble will reveal all sorts of deposits trapped within from many years of formation.
sometimes rock can get different color forms ''growing '' out of the rock or on the surface due to Bacteria populations, other microbial life and from the sea water reacting to the many deposits within the rocks layers.
Changes in Aquarium water can trigger die off events Or growth events of living organisms just as well can expose layers of rock previously not seen due to the coverage of coralline algae.
Years back we had an abundance of live rock available to us for use in this wonderful hobby. Just like a person has mentioned the black bands on and inside some of the rock we have seen patches of rusty looking orange, dark maroons, Blue, Black, yellow yada yada yada..... on and within the rock.
This is most likely coloration of the rock that has always been there or just below the surface a change in lighting or chemistry can cause coralline algae to die off exposing the rock to light for the first time in a long time so no telling what is under that pretty purple.

I once had two 180 gallon tanks plumbed into one system in which both were holding massive sized live rocks ranging from 30 to 80 pounds each.
Some of this rock had multiple dark to black spots while some had other colors of the rainbow, all to which did not bother anything.
Over time some of the spots were covered up with new growth of coralline algae and some covered by sponge and or feather dusters.
There is a soft to the touch dark purple coralline algae that only comes in on real reef live rock that I used to have lots of years back, most of it was either killed off by a power outage from a hurricane or got smothered out by the faster growing pink variety.
One small rock in my current tank still has a healthy complete coverage of this coralline and it prefers lower light or it bleaches out.
Usually when it gets covered up / smothered out or dies off is when I see spots like you pictured being exposed.
may have more to do with your coralline dying off in that particular area in my opinion.
Have you changed anything with your lighting or chemistry in the past few months ?

Thank you for your reply.

I have not adjusted anything in dosing but several months ago, I increased the lights on timing to 12 hours. It was 10 hours lights on for a span of years prior.

Recent test results:
ph-8.3
kh-10 dkh
ca-400 ppm
mg-1285 ppm (was usually 1350-1400 ppm)
no3- less than 1ppm
po4- less than .03 ppm

I was recently away on a short trip so I wasn't able to dose the reef the way I regularly do. I believe that this is why the magnesium was a little low. I have since corrected the level.

I also ran chemi-pure in the sump for one week, last week, in case there was anything in the water that may have been causing this.

Also, yesterday, I carefully treated the patches on one rock with peroxide. It didn't do anything to the black patches at the time. I will take a look a little later and report back.

 

[brandon429]

3% is weak, that's how we get away with dumping large amounts in certain challenge tanks without killing stuff besides the select few targets that respond to it in that manner but it's worth it to test just so we begin to find options.


Topically killing it may not work if it's deep seated, I have some certain driftwood with X invader encroaching my planted tank and last mo I took the wood out, soaked n a cooler of multiple bottles of 35% plus a little water, it was boiling chemically for hours and bleaching the wood...then i sun dried it for two days n backyard. Two weeks ago, the freak sprouted again right off the clean areas, on just this one piece. I will bake it at 250 for 24 hrs, let's party said organism. It'll still win, Jeff goldblum already said why

I like what blue water wrote above, these alternating generations which are currently selected for v against in the example reef may be working in terms of decades to cycle in or out... or maybe lessen if a better space competitor finds a support niche and can physically or chemically fight back, all for vital space. The rock is too good to give up on yep

 

[chris85]

What does your micro life look like? (worms,pods,mini stars)

 

[SnakeCharmer]

3% is weak, that's how we get away with dumping large amounts in certain challenge tanks without killing stuff besides the select few targets that respond to it in that manner but it's worth it to test just so we begin to find options.


Topically killing it may not work if it's deep seated, I have some certain driftwood with X invader encroaching my planted tank and last mo I took the wood out, soaked n a cooler of multiple bottles of 35% plus a little water, it was boiling chemically for hours and bleaching the wood...then i sun dried it for two days n backyard. Two weeks ago, the freak sprouted again right off the clean areas, on just this one piece. I will bake it at 250 for 24 hrs, let's party said organism. It'll still win, Jeff goldblum already said why

I like what blue water wrote above, these alternating generations which are currently selected for v against in the example reef may be working in terms of decades to cycle in or out... or maybe lessen if a better space competitor finds a support niche and can physically or chemically fight back, all for vital space. The rock is too good to give up on yep

The only two clues I see which seems to make this black stuff a "bad guy" is that it bleaches out the pink/purple/red coralline algae ahead of it's advancement (and it is still advancing) and that the yellow polyps on top of the black areas are withering.

 

[SnakeCharmer]

What does your micro life look like? (worms,pods,mini stars)

Not much of anything, probably due to having a hawkfish in there for years prior and now a six-lined wrasse. I do keep a colony of Cortez hermits and and a handful of Astrea snails in there. The only thing I can say with certainty that is growing on the rock aside from abundant coralline coverage, a few small areas of hair algae, and now this ever expanding black stuff, is a few patches of sponge on the underside/shaded areas of the reef rock.

If you have any suggestions, I am all ears.

 

[SnakeCharmer]

UPDATE: The older black patches (some of them, but not all) are fading or faded out to pale gray. There are still some new areas spreading/developing, though.

I am also seeing new growth areas of coralline algae.

The only extra things I have done in recent times are:

*blasting the live rock out with a pump and then vacuuming out the settled debris (was done two water changes in a row)
*ran Chemi-pure through the system for one week
*installed a small pump (200gph) to create current across the back of the live rock (former dead zone)

 

[BluewaterLa]

UPDATE: The older black patches (some of them, but not all) are fading or faded out to pale gray. There are still some new areas spreading/developing, though.

I am also seeing new growth areas of coralline algae.

The only extra things I have done in recent times are:

*blasting the live rock out with a pump and then vacuuming out the settled debris (was done two water changes in a row)
*ran Chemi-pure through the system for one week
*installed a small pump (200gph) to create current across the back of the live rock (former dead zone)

Could very well be a flow / oxygen issue with the rock and adding the extra flow after blowing out the detritus seems to have had a positive affect.
Glad to hear it and thank you for the update, Please update with any future progress or other.
The interesting thing about this hobby that keeps most of us captivated for years on end is the Unknown.
We will never know everything good or bad that happens in our tanks though we learn new things all the time.

Sometimes our rock gets really coated completely with coralline and this affects water passages / holes in the rock from being able to purge waste and keeps oxygen and water out of the rock compared to when it was not as covered.
I do think and believe that rock will go through some stages of rebirth so to speak naturally when conditions need to change or favor other organisms to become more prevalent. Could be that the black spots you were seeing was a natural cycle of die off for the rock to be able to cleanse itself for lack of better words.
I'm finding it hard to put into words what my tired brain is got brewing.
Any who thanks again for the update, I will look forward to any progress you decide to post up.
Thanks for sharing.

 

[Can_anne]

I also have similar black and gray patches killing the coralline algae in my 14-year-old reef tank. I first noticed them about a year ago and new patches have been forming ever since. The nearby corals are still healthy and so far the red coralline algae varieties that thrive in lower light have been spared.

The patches feel the same as the coralline algae and can’t be scratched off. I'm not really sure if light is a factor, but the the areas with thick pink-purple coralline at the top of my tank were hit the hardest. I turned over a large piece of live rock for about two months to see how the patches would react to shade, but they continued to spread.

I also took a piece of rock out of my tank and spot treated it with undiluted chlorine bleach for about 5 minutes. After thoroughly rinsing and dechlorinating the piece of rock, I put it back in the tank. The bleach wasn't able to penetrate deep enough and the indestructible black patch was moving again in no time!

 

[brandon429]

This thread contains the best quality live rock I’ve seen in home reefing

The invasion challenges are secondary to the awesome knurled nature of the above

Great thread

 

[SnakeCharmer]

I also have similar black and gray patches killing the coralline algae in my 14-year-old reef tank. I first noticed them about a year ago and new patches have been forming ever since. The nearby corals are still healthy and so far the red coralline algae varieties that thrive in lower light have been spared.

The patches feel the same as the coralline algae and can’t be scratched off. I'm not really sure if light is a factor, but the the areas with thick pink-purple coralline at the top of my tank were hit the hardest. I turned over a large piece of live rock for about two months to see how the patches would react to shade, but they continued to spread.

I also took a piece of rock out of my tank and spot treated it with undiluted chlorine bleach for about 5 minutes. After thoroughly rinsing and dechlorinating the piece of rock, I put it back in the tank. The bleach wasn't able to penetrate deep enough and the indestructible black patch was moving again in no time!

Thank you for sharing. That is indeed exactly what I have going on in my reef. It's the purple coralline algae that is specifically being attacked in my reef as well. That could be a key detail.

I am considering trying the live spore purple coralline enhancer product that reef keepers are talking about to see if there is any reaction or improvement. As I stated earlier, there is some areas of new growth/unaffected purple coralline in my reef, specifically at the edges of the reef. But overall, the blackening, then graying of many of the live rocks continues.

 

[biecacka]

Has anyone sent @brandon429 or anyone else in the science arena a sample of their black rock?

Corey

 

[SnakeCharmer]

Has anyone sent @brandon429 or anyone else in the science arena a sample of their black rock?

Corey

Should I? How?

 

[brandon429]

Team I wouldn't be of much help with it, this is all uncharted territory. This type of growth on live rocks of this diversity and quality and time to alternate generations of creatures is going to unfold with unmapped challenges, that's rather unique compared to freshwater planted tank work where its pretty predictable. Amazing what reefs throw at us given time, given real maturation time on a rare scale. Im watching and taking notes from others

merely relocating the sample away from its substrate base would likely alter all testing/eradication steps tried upon receipt, this is truly a whole-tank challenge unfolding in live time.