Dissolved Organic Carbon and Coral Disease

[Mattrg02]

Since I retired last April I have spent a lot of time looking at the whole picture of my tank.
Smell to me equals either massive amounts of bacteria releasing that swamp smell or just massive amounts of organics.
I swear I can see negative coral reaction with these high amounts or I just might have too much time on my hands.
Ya also I have been doing this PH thing for quite some time.
In my theory the amount of carbons, organics and bacteria break down in the ph test and drops the ph to that yellow.
I keep a "control" test from my new salt water and it never changes color. So this is how I correlated load.

My water, even skimmate, smells floral. My rocks do not, smell odd.

 

[Randy Holmes-Farley]

My skimmate has never smelled bad either. I think that is a function of the types of organic matter being produced in the tank.

 

[sonnus]

I completely agree with this idea from my personal experiences too. I have not only had massive coral death events but also fish deaths. When the last event occurred I hired a marine veterinarian to perform gill clipping biopsy on a live fish and he found massive bacteria and ciliate populations. He suspected that carbon dosing was causing bacteria growth and in turn the ciliate growth. He also aspirated fluid from "cysts" on acropora and found the same thing. The ciliates that were present on the acros were very similar to those found on acros with brown band disease in the Caribbean. There have been several articles published correlating DOCs with brown band disease in the Caribbea (and of course other coral diseases).

A major problem with carbon dosing is adding carbon when no nitrate or phosphate is detectable. The vet mentioned that once the N and P are limited the "good" bacteria cannot thrive and the excessive carbon in the aquarium fuels the pathogenic bacteria growth. Continuous carbon dosing is dangerous and, in my opinion, this is why biopellets should be a major concern for those experiencing these types of losses. Biopellets are uncontrolled carbon dosing to the aquarium and this is what I attribute to all of the events I experienced. I still carbon dose but only after I measure detectable nitrates and phosphates first. If either of the N or P is undetectable I don't dose. I also always dose TLF Bactiv8 od Dr. Tim's Waste Away when carbon dosing.

 

[robert]

Hi Robert, I asked in your other thread about the details of that blue chart since it isn't clear what they did over 30 days. Continuously maintaining those organic concentrations at that level might require effective doses higher than any typical reefer uses with organic carbon dosing, and apparently dropping the dose a bit brings it back in line with their controls.

That said, I do not recommend that people use sugars.

also in reply to your post in my corals become thin:
"I've never been a fan of sugar dosing, but that said, do you have a link to that paper so I can see what they actually did?

For example, was carbon maintained at that concentration for 30 days, or a single dose?"

This thread second post has the link to the paper:

the second chart show the explosive growth in microbia populations within the scm of the coral starts 26 hours after exposure -

http://www.researchgate.net/profile..._Mortality/links/0deec5266a31792079000000.pdf

 

[Randy Holmes-Farley]

Thanks.

I don't doubt, obviously, that the added organics drove bacteria levels up. But I question whether that is the primary or sufficient cause of the problems.

I'm concerned about interpreting this data as a DOC problem and not, perhaps, an excessively low N and/or P problem due to the growth of bacteria (which we all have learned is an issue that these folks might not have understood back when they did this experiment more than a dozen years ago).

They started with seawater, with its inherently low N and P, and drove a LOT of bacterial growth with high sugar doses. IMO, this is not what reefers do.

They also didn't dose these organics the way a reefer would, but started fast and maintained it at a certain concentration. Their initial doses were already quite high (equivalent to an initial dose of 24 mL of vodka or 189 mL of vinegar to a 100 gallon tank), and they held the concentration there (which reefers do not so).

We do not know how fast the organics are normally consumed, but I believe it is not longer than a few hours in a reef tank that has been getting this organic for a week or two already so has lots of bacteria. Let's assume 4 h is a half life for added organic matter like acetate or sugar or ethanol. Then they would be effectively adding several (3) times this "initial dose" every day. So they might be adding the equivalent of 75 mL of vodka or 567 mL of vinegar to a 100 gallon tank that has N and P starting at low levels to begin with.

IMO, that is a recipe for problems.

 

[Mattrg02]

Let's say that high DOC drove up bad bacteria and that caused a breakout of stn. What would be the best way to clear this up? Heavy skimming, as in, wet skimming? Bacteria dosing such as MB7? Or both?

Before my montiporas started to have stn issues, I had an unknowingly ulns. Once I figured that out, I started over feeding and saw some bacteria blooms. It wasn't long before some montiporas began dying out of nowhere. Could these bacteria blooms possibly been some kind of nasty bacteria that overwhelmed my montiporas? Strangely, no acroporas seemed to care.

 

[Randy Holmes-Farley]

Let's say that high DOC drove up bad bacteria and that caused a breakout of stn. What would be the best way to clear this up? Heavy skimming, as in, wet skimming? Bacteria dosing such as MB7? Or both?
.

Depends on the organic. If it is natural organic stuff in the tank, skimming, GAC, and Purigen are all good choices, and all three could be used at the same time. They can remove some of it quite well, but not all organics can be removed this way.

If it is acetate from vinegar dosing, or sugar, or likely ethanol, there's nothing you can do except water changes or let it decline on its own from bacterial metabolism. Skimming and GAC and (probably) Purigen won't remove them.

 

[sonnus]

Let's say that high DOC drove up bad bacteria and that caused a breakout of stn. What would be the best way to clear this up? Heavy skimming, as in, wet skimming? Bacteria dosing such as MB7? Or both?

Once the RTN starts I immediately dip the coral in Lugol's solution. Most coral dips that we use have poor antibacterial properties and I think that the Lugol's might be the best option. I use Tropic Marin Pro-Coral Cure at about twice their recommended dose. I personally do not frag the corals, I have tried both ways (fragged and not fragged) and I've had better success not fragging. Also, don't pop any cysts that appear, this will lead to immediate RTN. Many times if the cysts are left alone they resolve on their own.

You can also move the coral to another tank if possible. I've had great success moving coral to other tanks not experiencing the problem and I've never had corals in the new tank affected by the same disease.

 

[Randy Holmes-Farley]

I'm not sure if MB7 will reduce the overall DOC (although it possibly might). It actually also contains DOC's.

 

[sonnus]

Can ORP be a reliable method of tracking DOCs in our aquariums if it were used in conjunction with pH, O2 and CO2?

 

[Randy Holmes-Farley]

Can ORP be a reliable method of tracking DOCs in our aquariums if it were used in conjunction with pH, O2 and CO2?

I do not know the answer since I've not seen enough DOC/ORP data to say, but ORP might reflect DOC's, modified for a variety of other factors specific to the tank, such as the nature of chemicals dosed, etc.

I think it more likely reflects the oxidation state of the organics and especially the trace metals rather than the total amounts.

For example, ozone is obviously known to raise ORP, but it does not reduce organic levels. It just oxidizes the organics present but mostly leaves them there.

 

[twilliard]

So randy what this all comes down too is that there is no good method of determining doc's except our senses?
I ask this because I use the triton method and don't change water BUT my concern is elevated doc's which I can see as a film and by the smell of the water.
So carbon and skimming is the best solution to keep these doc's down?

 

[Randy Holmes-Farley]

So randy what this all comes down too is that there is no good method of determining doc's except our senses?
I ask this because I use the triton method and don't change water BUT my concern is elevated doc's which I can see as a film and by the smell of the water.
So carbon and skimming is the best solution to keep these doc's down?

The "Send it out" method is total organic carbon. This lab does it for reef aquaria:

http://www.enclabs.com/details.html#toc

 

[robert]

Hi Robert!
About this post it closely follows what I do with a standard ph test.
Same principal and theory.
I run a ph test daily but not to see what my ph is.
In a given amount of time the test will turn yellow from its original purple (Elos ph)
I take this time to determine .. well bacteria, organics, fish waste volume in my tank.
My average color shift is 8-10 hours
When if falls bellow this under 8 hours I change my carbon and up the skimmer a tad.
In 48 hours my color shift is back within the 8-10 hour mark

Here is this morning load test

Thats an amazing observation - can you reproduce it? Could you take some fresh mix and compare it to tank water? I can't reptend to undestand the mechanisms - but if it were to be an indication of DOC we'd call it "twillards test" and you'd be famous...

Seriously, your very observant...I've notice the color shift and never thought anything of it.

 

[robert]

FWIW, while I think it is a fine hypothesis that dissolved carbon may be a problem in some reefs, I do not think it is clear that general DOC's have caused an issue in typical aquaria (except cyanobacteria, which is very likely).

This is an interesting point. Through what mechanism do you propose that carbon dosing elicits cyano growth and why would that not be indicative of a problem?

Cyano itself is a producer of DOC compounds which are hypothesized to be part of the conversion of coral reefs to algae domination. Destroys the corals and leads to algae overgrowth.

cyano and carbon dosing may be a double strike.

 

[robert]

Hi Robert, I asked in your other thread about the details of that blue chart since it isn't clear what they did over 30 days. Continuously maintaining those organic concentrations at that level might require effective doses higher than any typical reefer uses with organic carbon dosing, and apparently dropping the dose a bit brings it back in line with their controls.

That said, I do not recommend that people use sugars.

Marco algae and cyano produce and release sugars (DOC)...and in surprisingly high concentrations and in some cases forms which are detrimental to corals. How does one propose to determine the initial carbon load on a system prior to instituting a dosing regimen.?

 

[robert]

I completely agree with this idea from my personal experiences too. I have not only had massive coral death events but also fish deaths. When the last event occurred I hired a marine veterinarian to perform gill clipping biopsy on a live fish and he found massive bacteria and ciliate populations. He suspected that carbon dosing was causing bacteria growth and in turn the ciliate growth. He also aspirated fluid from "cysts" on acropora and found the same thing. The ciliates that were present on the acros were very similar to those found on acros with brown band disease in the Caribbean. There have been several articles published correlating DOCs with brown band disease in the Caribbea (and of course other coral diseases).

A major problem with carbon dosing is adding carbon when no nitrate or phosphate is detectable. The vet mentioned that once the N and P are limited the "good" bacteria cannot thrive and the excessive carbon in the aquarium fuels the pathogenic bacteria growth. Continuous carbon dosing is dangerous and, in my opinion, this is why biopellets should be a major concern for those experiencing these types of losses. Biopellets are uncontrolled carbon dosing to the aquarium and this is what I attribute to all of the events I experienced. I still carbon dose but only after I measure detectable nitrates and phosphates first. If either of the N or P is undetectable I don't dose. I also always dose TLF Bactiv8 od Dr. Tim's Waste Away when carbon dosing.

Thats an amazing vet. Better than most doctors who treat people. Did he prepare any report? Likely not but I'm sure it would have besn an interesting read. I agree with your colclusions and your vets.

 

[robert]

Thanks.

I don't doubt, obviously, that the added organics drove bacteria levels up. But I question whether that is the primary or sufficient cause of the problems.

I'm concerned about interpreting this data as a DOC problem and not, perhaps, an excessively low N and/or P problem due to the growth of bacteria (which we all have learned is an issue that these folks might not have understood back when they did this experiment more than a dozen years ago).

They started with seawater, with its inherently low N and P, and drove a LOT of bacterial growth with high sugar doses. IMO, this is not what reefers do.

They also didn't dose these organics the way a reefer would, but started fast and maintained it at a certain concentration. Their initial doses were already quite high (equivalent to an initial dose of 24 mL of vodka or 189 mL of vinegar to a 100 gallon tank), and they held the concentration there (which reefers do not so).

We do not know how fast the organics are normally consumed, but I believe it is not longer than a few hours in a reef tank that has been getting this organic for a week or two already so has lots of bacteria. Let's assume 4 h is a half life for added organic matter like acetate or sugar or ethanol. Then they would be effectively adding several (3) times this "initial dose" every day. So they might be adding the equivalent of 75 mL of vodka or 567 mL of vinegar to a 100 gallon tank that has N and P starting at low levels to begin with.

IMO, that is a recipe for problems.

One of the problems in reading a study in such a short time is "confirmation bias". You tend to dismiss information which does not fit your belief systems. I do it - everyone does.

The purpose of the study was not to investigate DOC in fish tanks but investigate potential effects carbon pollution of reef systems in the wild. Increased dosing is common in these types of studies, first to identify the "potential" of a problem and secondly to differentiate between acute anc cronic conditions. Perfect? - No.

Despite this it does bring forward new information which we might benefit by incorporating into our tanks and husbandry practices. First and most obviously, and one with which you seem to agree is that its probably not a good idea to dose sugar.

You admit you we don't know the dwell time of DOC in our systems but you venture that it is not more than a "few hours". Then you calculate based on that assumption to demonstrate that the experiment operated outside of tank parameters and methods. Can you back this up in any emperical way. Have you considered that dosing may not be the only source of DOC in the system? Have you included bacterial contributions, potential cyano and macoalgae contributions? Corals themselves contribute to DOC on the reef an in out tanks with the SCM they produce which by all acounts has an extened dwell time as its not easily broken down by many common bacteria.

I might postulate that jumping to defend an idea without careful consideration is a sign of potential confirmation bias.

This study is well structured, well documented, run by reputable non-commercial institutions without a product to push. I think really good questions arise.

No one to my knowledge selling product has done anything along these lines. While carbon dosing looks to be a promising methodology for nutrient export, the lack of basic investigation into the potential downsides is a little disturbing.

In an earlier post you advocated vinegar over vodka. Why? has that been studied in any systematic or even simply controlled manner - or is all the evidence anecdotal?

Lots of very good hints in that article - follow the citations -

 

[twilliard]

Thats an amazing observation - can you reproduce it? Could you take some fresh mix and compare it to tank water? I can't reptend to undestand the mechanisms - but if it were to be an indication of DOC we'd call it "twillards test" and you'd be famous...

Seriously, your very observant...I've notice the color shift and never thought anything of it.

Ya I can reproduce this daily.
For instance yesterdays test was completed in 7 hours. Way too soon for me. I love to ask myself why the color shift so soon? So I dug into the the question
Carbon is 10 days old, can't be depletion yet.
Moved on the the skimmer.. hmm minimal foam for 2 days now??
So I pulled the skimmer pump, take the housing off and what is this? The needle wheel was absolutely full of my baby trocious snails (they breed like mice) and this morning bio film in the fuge is gone.
I started my PH test at 7 am and shall see if my skimmer has made any difference in the time change.



Left is tank water right is fresh saltwater
I will post a picture later showing the change

 

[Randy Holmes-Farley]

This is an interesting point. Through what mechanism do you propose that carbon dosing elicits cyano growth and why would that not be indicative of a problem?

Cyano itself is a producer of DOC compounds which are hypothesized to be part of the conversion of coral reefs to algae domination. Destroys the corals and leads to algae overgrowth.
.

Cyanobacteria can also consume organics from the water (not generally the same ones they release), and if you have a species of cyano that thrives on the particular organic you use, that is obviously a big drawback and a potential reason to stop dosing that organic.