High Levels of TOC in the Reef

[Garf]

Isn’t TOC fish corals and all the little stuff?

 

[Daniel Almeida Prado]

I am highly skeptical that high TOC in general is killing your corals.

what level did they detect?

Many thanks for the answer Handy!!!!

Triton N-doc tests

TIC 29.75 - pretty good
TOC 12.33 (0-4 setpoint) - bad
TC 42.09 - good
TNb 4.24 - bad

They use a analogy to explained to me. A reef with the TOC level of my aquarium, would be the same of a reef with 32degrees.

They also think that TOC level is the cause of my corals death!!!!

Daniel

 

[Cory]

Hello Cory,

many thanks for your help.

I also suspected of that. I emailed Weber and talk to an engineer of that area and the answers are not convincence for me.

So, a few years ago I take off that cement and today the reef is running with aragonite substrate.

Daniel

Well then next in line is your rocks. Are they actually old live rock? Or mined rock?

 

[Dan_P]

The last N-doc Triton tests:

TIC 29.75 - pretty good
TOC 12.33 (0-4 setpoint) - bad
TC 42.09 - good
TNb 4.24 - bad

Following Triton, that high level of TOC increases the NO3 levels, in my case 18.74.

These alterations generate bacterial blooms causing a lack of oxygen according Triton.

So, I am still trying to find the carbon source.

Just to put things in perspective, a 1 mL / gallon dose of vinegar is about 5 ppm. In my system this can cause cloudy water, but oxygen level 6-7 ppm does not suffer. Your carbon level is 2.5 times higher. This level is one the highest I came across in my small database (picture below). You should discuss your issue with @Lasse a d @Sallstrom .

1) What is oxygen level in your system?
2) Is the water constantly cloudy? Are surfaces covered with white slime?
3) What is the nature of the organic material? Have you determined the biological oxygen demand of your water? Is it high? Not many people use this method, but the few that do find the BOD5 to be <1 ppm (@Dana Riddle, @taricha). If your organic matter is bacteria food, the BOD5 could be substantial.

The nature of the organic matter is important. If it digestible, bacteria will use it and cloud the system, possibly it can encourage bacteria growrth detrimental to coral. Or the organic matter is not very digestible, is not readily removed by bacteria or skimming (do you run granular activated carbon?) and its level never changes. And it is toxic to invertebrates. Some type of contamination that continues to leach from equipment although it is not clear to me whether your system was initially contaminated and the pollutant was never removed or it us continually contaminated.

Have you attempted to purify a sample of the water by recirculating it through a column of GAC, GFO, or aragonite?

 

[Cory]

Can you post the icp results? Im curious of your salinity because all fish staying alive but corals dying says salinity to me.

 

[Lasse]

I´ll think that @Dan_P have some very interesting questions. Depending on your answers - this can indicate if the excess TOC is caused by biological "fast working organic carbon sources" or more hard-to-decompose chemical organic carbon sources. If you are able both to take a BOD5 and a COD measurement - it could be to some help.

What I have read (and understand) there is some indications that your problem consist of hard-to-decompose organic carbon sources. This type of organic carbon sources include mineral oils, certain pesticides, essential oils (common in scented candles), humic acids and lot of other hydrocarbon products.

Do you use GAC (active carbon) - it should be able to take away some of these products, so could ozone and hydrogen peroxide too. Have you test either to filtrate over CAC ( a small amount that circulate over a GAC filter for a day or two) or treat a sample heavily with ozone and after that test it for TOC at Triton

You have part of your system outside - It looks like you live near the sea - not in a City center.

In the thread you mention - I saw a picture that can be a longshoot

The part in the red circle indicate that this is pipes for waste or drain water (it looks like they have a rubber fitting). There was a rumor here in Sweden that this type of PVC or PP pipes could have been treated with anti fouling agents. It looks like your pipes are PVC because I can see glued joints too. (you can´t glue PP) The ones here in Sweden was orange and PP. I do not think it is this way in your system because it should have killed fish too - but I think it worth to be mentioned

My 9 TOC test is between 5.9 to 8.5 mg/L. I have been up to nearly 4 mg/L of TNb - normally around 2. Have you done good NO3 tests - and if - are most of your TNb mostly NO3?

Finally a rather odd question - how is the growth of algae on your windows? Good. normal or badly. If badly - can you aim a light source at the inside of the glass (at a certain point) and see if you get som algae growth during a week or two at that point.

Sincerely Lasse

 

[Sallstrom]

I’ve had a quick look through our N-DOC results from work (public aquarium) too see if I can see any relationships between high TOC and any other result.
I haven’t found any apparent connections yet.
We have had two systems with high TOC, around 8,5. Both cold water systems with rather high nutrient levels. And probably with some remains of died off kelp/macro algae in the systems. Also lots of food added, like shrimps, clams and live phytoplankton and artemia. “Heavier” food then in our tropical tanks.
Just some info, not sure if it could help.

Also, have you only done one N-DOC test? If so you perhaps could do one more to see if the first one was correct.
I think if you get in touch with Triton and ask them to test the second vial you already sent as well, that could also be possible. Just to be able to trust the result before starting to change things.

Good luck!

 

[Daniel Almeida Prado]

Well then next in line is your rocks. Are they actually old live rock? Or mined rock?

Hello Cory,

At the beggining I used a mix of old and new live rock. 3 years ago I have changed all the rocks for new live rocks.

 

[Daniel Almeida Prado]

Just to put things in perspective, a 1 mL / gallon dose of vinegar is about 5 ppm. In my system this can cause cloudy water, but oxygen level 6-7 ppm does not suffer. Your carbon level is 2.5 times higher. This level is one the highest I came across in my small database (picture below). You should discuss your issue with @Lasse a d @Sallstrom .

1) What is oxygen level in your system?
2) Is the water constantly cloudy? Are surfaces covered with white slime?
3) What is the nature of the organic material? Have you determined the biological oxygen demand of your water? Is it high? Not many people use this method, but the few that do find the BOD5 to be <1 ppm (@Dana Riddle, @taricha). If your organic matter is bacteria food, the BOD5 could be substantial.

The nature of the organic matter is important. If it digestible, bacteria will use it and cloud the system, possibly it can encourage bacteria growrth detrimental to coral. Or the organic matter is not very digestible, is not readily removed by bacteria or skimming (do you run granular activated carbon?) and its level never changes. And it is toxic to invertebrates. Some type of contamination that continues to leach from equipment although it is not clear to me whether your system was initially contaminated and the pollutant was never removed or it us continually contaminated.

Have you attempted to purify a sample of the water by recirculating it through a column of GAC, GFO, or aragonite?

Hello Dan_P,

Many thanks for your help.

Good to know that my TOC level is one the highest that you have in your database. The help from @Lasse and @Sallstrom will be very apreciate for me.

The answers:

1 - I do not know what is the oxygen level today, but I will try to measure the level later and post here. In the past the level was normal.

2 - The water isn't cloudy, however it has also never been cristal clear (good point Dan_P). I don't have white slime in the reef.

3 - I do not understand that question about the natura of the organic material. How can I determine the biological demand of the oxygen of my reef? I will read about BOD5.

I do not run actived carbon at this moment.

I never try to purify a sample of water. How can I do this kind of test? Could you please explain for me?

Daniel

 

[Daniel Almeida Prado]

Isn’t TOC fish corals and all the little stuff?

Garf,

Excuse-me, I do not understand what you mean......

 

[Daniel Almeida Prado]

Can you post the icp results? Im curious of your salinity because all fish staying alive but corals dying says salinity to me.

Hello Cory,

For sure. I will post the last ICP and N-Doc from the this month.

N-Doc tests:

ICP Tests:

 

[Daniel Almeida Prado]

I´ll think that @Dan_P have some very interesting questions. Depending on your answers - this can indicate if the excess TOC is caused by biological "fast working organic carbon sources" or more hard-to-decompose chemical organic carbon sources. If you are able both to take a BOD5 and a COD measurement - it could be to some help.

What I have read (and understand) there is some indications that your problem consist of hard-to-decompose organic carbon sources. This type of organic carbon sources include mineral oils, certain pesticides, essential oils (common in scented candles), humic acids and lot of other hydrocarbon products.

Do you use GAC (active carbon) - it should be able to take away some of these products, so could ozone and hydrogen peroxide too. Have you test either to filtrate over CAC ( a small amount that circulate over a GAC filter for a day or two) or treat a sample heavily with ozone and after that test it for TOC at Triton

You have part of your system outside - It looks like you live near the sea - not in a City center.

In the thread you mention - I saw a picture that can be a longshoot

The part in the red circle indicate that this is pipes for waste or drain water (it looks like they have a rubber fitting). There was a rumor here in Sweden that this type of PVC or PP pipes could have been treated with anti fouling agents. It looks like your pipes are PVC because I can see glued joints too. (you can´t glue PP) The ones here in Sweden was orange and PP. I do not think it is this way in your system because it should have killed fish too - but I think it worth to be mentioned

My 9 TOC test is between 5.9 to 8.5 mg/L. I have been up to nearly 4 mg/L of TNb - normally around 2. Have you done good NO3 tests - and if - are most of your TNb mostly NO3?

Finally a rather odd question - how is the growth of algae on your windows? Good. normal or badly. If badly - can you aim a light source at the inside of the glass (at a certain point) and see if you get som algae growth during a week or two at that point.

Sincerely Lasse

Hello Lasse,

Many thanks for your kindly answer!!!!

As I said to Dan_P, since the beggining the reef water aspect of the aquarium was a bit diferent from my older tanks. A little bit less clarity than the others, but I always thought that the reason for that is the size of the tank. Do you recommend to make the BOD5 and COD test in what kind of company? Because I do not know what kind of company can do it these tests with acurracy.

I undestood your point o f view about hard-to-decompose organic carbon sources and I completely agree with you. I am trying to find that sources in my reef exhaustively.

About your idea to ozone the water or use a GAC filter - During 3 months I ozone (4g ozone generator) the RO-DI water exhaustively before to feed the reef, I also ozone the reef (380ppm). After 3 months I sent the water to Triton and no kind of benefits, unfortunately.

I live a little bit far from the Sea, in a small town too far the big cities.

Very good point about the pipes - The pipes that you can see in the picture is really a waste pipe and I glued all of the connections, but I never had any problems with fishes deaths.

To measure NO3 I use a simple test from ReefForest and the level is always 0.10ppm. The Triton test calculate the TnB of the reef in 4.24mg/l and the NO3 in 18.74 mg/l.

I will take pictures from the reef. A lot of algaes in all spaces. Terribly ugly, discouraging.......

Warm regards,

Daniel

 

[taricha]

3 - I do not understand that question about the natura of the organic material. How can I determine the biological demand of the oxygen of my reef? I will read about BOD5.

The BOD5 test is simple if you have an oxygen meter, which you indicate you do. Fill a volume of a clean container with tank water (well aerated - measure O2) and seal it air-tight with no bubbles inside. Let it sit sealed in the dark at room temp (~20 C) for 5 days. Then measure O2 again.

The BOD5 of aquarium water should be small - less than 1 or 2 mg/L O2 decrease out of max ~7mg/L. If your TOC number is as high as triton reports, you might fully deplete nearly all available O2 in the water over 5 days.

If it were me, and this were the case - high BOD5 - I would test the tank water for BOD5 filtered through a <1 micron filter (0.2 micron would be ideal). And compare to the BOD5 for unfiltered.
This would tell me if my high organic carbon were mostly Particulate or Dissolved.
If particulate, I would increase skimming, mechanical filtration etc.
If dissolved, I would increase the use of GAC.

 

[Daniel Almeida Prado]

I’ve had a quick look through our N-DOC results from work (public aquarium) too see if I can see any relationships between high TOC and any other result.
I haven’t found any apparent connections yet.
We have had two systems with high TOC, around 8,5. Both cold water systems with rather high nutrient levels. And probably with some remains of died off kelp/macro algae in the systems. Also lots of food added, like shrimps, clams and live phytoplankton and artemia. “Heavier” food then in our tropical tanks.
Just some info, not sure if it could help.

Also, have you only done one N-DOC test? If so you perhaps could do one more to see if the first one was correct.
I think if you get in touch with Triton and ask them to test the second vial you already sent as well, that could also be possible. Just to be able to trust the result before starting to change things.

Good luck!

Many thanks Sallstrom,

I did ate least 6 Triton tests in the last 12 months. All of these with the high TOC levels. After a lot of talks, the Triton said to me to try to find some kinf of the source of the TOC.

Good to know about your experience that systems with high TOCs.

Regards,

Daniel

 

[Lasse]

Every environmental lab can do both BOD5 (or BOD7 in some countries) and COD tests. They normal also know the normal ratio between them. The BOD5 (7) give you a hint of how much your "easy to handle organic carbon" you have and the COD minus BOD5(7) give you a hint how much "hard to decompose organic" carbons you have. You can´t direct translate this to the figures from Triton - Triton show mg/L of organic carbon and BOD/COD show mg/L oxygen consumed in order to oxidize the organic carbon into inorganic - but you will have the ratio and a hint what you should try to found)

If your BOD5(7) is low - most of the TOC from Triton must be from sources that is difficult to decompose and potential toxic substances as @taricha indicate

If you treat some litre of aquarium water with re-circulation over GAC for some days (or heavily dosing Ozone) and after that send in a NDOC test you may get an idea of the type of organic carbon in the Triton test

IME the tiny green algae that grow on the windows is among the most sensitive organisms I know. If it not is difficult - make the experiment

Sincerely Lasse

 

[AquaBiomics]

The discussion about refractory DOC versus labile DOC is valuable, and I don't mean to distract from it by bringing up other issues. I'm still stuck on the question of "where is it coming from in the first place"?

How does TOC in your system behave following water changes, especially larger water changes? How quickly does it come back up? (I think water changes are not a frequent thing in the "Triton system", but am not sure... )

I'm not trying to get you to start doing lots of water changes, just trying to diagnose.

 

[Lasse]

The high TNb and your low nitrate readings In my samples - the NO3-N part of the TNb result normally is around 0.35 % - it means that if your samples follow that - you should read between 6-7 mg/l NO3 with your test - not 0.1. Please confirm your test with another test - I like the Tropic Marine PRO NO2/NO3 test kit - Salifert can work too

Sincerely Lasse

 

[Daniel Almeida Prado]

Every environmental lab can do both BOD5 (or BOD7 in some countries) and COD tests. They normal also know the normal ratio between them. The BOD5 (7) give you a hint of how much your "easy to handle organic carbon" you have and the COD minus BOD5(7) give you a hint how much "hard to decompose organic" carbons you have. You can´t direct translate this to the figures from Triton - Triton show mg/L of organic carbon and BOD/COD show mg/L oxygen consumed in order to oxidize the organic carbon into inorganic - but you will have the ratio and a hint what you should try to found)

If your BOD5(7) is low - most of the TOC from Triton must be from sources that is difficult to decompose and potential toxic substances as @taricha indicate

If you treat some litre of aquarium water with re-circulation over GAC for some days (or heavily dosing Ozone) and after that send in a NDOC test you may get an idea of the type of organic carbon in the Triton test

IME the tiny green algae that grow on the windows is among the most sensitive organisms I know. If it not is difficult - make the experiment

Sincerely Lasse

Perfect Lasse,

I will try some company to do the tests. What do you think to perform the test with a simple reef O2 Dissolved test as @taricha explained? I asked because I suspect that kind of enviromental company test will be dificult to find.

About the test with GAC or Ozone in a sample, I will do that!!!!

About the green algae, I did that test. I turn off the light of my refugium and that kind of tiny green algae has gone, completely.

 

[Daniel Almeida Prado]

The BOD5 test is simple if you have an oxygen meter, which you indicate you do. Fill a volume of a clean container with tank water (well aerated - measure O2) and seal it air-tight with no bubbles inside. Let it sit sealed in the dark at room temp (~20 C) for 5 days. Then measure O2 again.

The BOD5 of aquarium water should be small - less than 1 or 2 mg/L O2 decrease out of max ~7mg/L. If your TOC number is as high as triton reports, you might fully deplete nearly all available O2 in the water over 5 days.

If it were me, and this were the case - high BOD5 - I would test the tank water for BOD5 filtered through a <1 micron filter (0.2 micron would be ideal). And compare to the BOD5 for unfiltered.
This would tell me if my high organic carbon were mostly Particulate or Dissolved.
If particulate, I would increase skimming, mechanical filtration etc.
If dissolved, I would increase the use of GAC.

Many thanks Taricha,

Clear explanation!!!

Do you think that I can perform this test with a simple reef O2 dissolved water test?

Rgds,

Daniel

 

[Daniel Almeida Prado]

The discussion about refractory DOC versus labile DOC is valuable, and I don't mean to distract from it by bringing up other issues. I'm still stuck on the question of "where is it coming from in the first place"?

How does TOC in your system behave following water changes, especially larger water changes? How quickly does it come back up? (I think water changes are not a frequent thing in the "Triton system", but am not sure... )

I'm not trying to get you to start doing lots of water changes, just trying to diagnose.

Hello AquaBiomics,

Perfect point of view. Where is it coming from? That is the question. I did 10% weekly water changes for at least 5 weeks and I did a new Triton test. The same parameters, high TOCs!!!!

Rgds,
Daniel