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Belgian Anthias
01/01/2018, 07:51 AM
Nitrate assimilation

Nitrate assimilation is subjected to regulation that may differ depending on the organism. In general, nitrate assimilation is controlled at the transcriptional level by nitrate and nitrite induction and by ammonium repression.
In the pre-genome sequence era, it was known that some, but not all, heterotrophic bacteria were capable of growth on nitrate as a sole nitrogen source. However, examination of currently available prokaryotic genome sequences suggests that assimilatory nitrate reductase (Nas) systems are widespread phylogenetically in bacterial and archaeal heterotrophs.
In cyanobacteria, the transcription factor represses nitrate assimilation genes when ammonium is present whereas it activates transcription of these genes at a high
carbon/nitrogen ratio.
The nitrate-assimilation process begins with the transport of nitrate into the cell. Nitrate is further reduced to nitrite in a two-electron reaction by a cytoplasmic molybdenum containing nitrate reductase followed by a six-electron nitrite reduction to produce ammonia.
The assimilatory reduction of nitrate to ammonium is an energetically expensive process since it requires eight electrons and complex prosthetic groups for the nitrate and nitrite reductase enzymes, in addition to the active nitrate transport. In order to avoid this energetic cost under unnecessary environmental conditions, bacteria have evolved a strict control of the expression of the Nas system. Thus expression of the Nas genes is subjected to dual control based on specific nitrate or nitrite induction, and ammonium repression, by a general nitrogen-regulatory system. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:bio-chemie:nitraat_reductie

When adding carbohydrates for the first time not a lot will change to the nitrate level. Ammonia, normally nitrified by autotrophs, is used first . Only when the supply of ammonia is insufficient nitrate will be used. When dosing is continued nitrification will be suppressed due to ammonia availability as the heterotrophs grow a lot faster. Heterotroph ammonium reduction ( assimilation) produces 40 x more bio mass compared to autotroph ammonia reduction. ( http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:ammonium_reductie ) As a result less nitrate will be produced. The moment the C:N ratio increases due to dosing and increased ammonium take up ( and less or no nitrate production) nitrate may be used for celsynthesis. Nitrate is also taken up for respiration. Nitrate take up for respiration is not suppressed by ammonia. The nitrate level may be depleted fast at high C:N ratio. All this implements a very low nitrification and denitrification capacity.
When biopellets are used in a reactor there is always a high C:N ratio available.

An aquarium system that is kept in balance by carbohydrate dosing has a limited carrying capacity. Such systems are vulnerable for a system crash due to the well known new tank syndrome.
Once started dosing it may be difficult to stop. Dosing should be build off during a period of at least 15 days.

Please comment.

sde1500
01/01/2018, 09:23 AM
Well that made my head feel funny lol. Question though, you keep saying Carbohydrates, do you mean Carbon? Never heard of Carbohydrate dosing.

DiscusHeckel
01/01/2018, 10:07 AM
Thanks for sharing your knowledge. Some of the technical jargon in your post is beyond my level.

Assuming that you meant organic carbon by "carbohydrates", what you stated makes sense and is in fact well established in the literature. It is well known that reef organisms have preference for ammonia over nitrates for their nitrogen source. Daniel Knop and Michael Fatherree, for example, mention this phenomenon in their respective books on giant clams.

I also agree with your statement that "Once started dosing it may be difficult to stop". I think if one decides to stop dosing organic carbon, he/she should do so in small steps instead of in a big bang approach. Last summer, I experimented with a commercial product that contains marine-based biopolymers in it. It is marketed as Reef Actif by Tropic Marin. Even though I knew that I should decommission the use of this product slowly when my experiment finally finished at the end of last October, I went against my own knowledge and stopped using it at once. My reef system did not crash, but it was seriously destabilised in terms of nutrients and their ratio. It took nearly two months to regain its balance and it is still not quite there yet.

Moreover, in case you do not know, there is another commercial product marketed by Tropic Marin called NP-Bacto-Balance. It contains among other ingredients (e.g. organic carbon) organic and inorganic forms of phosphates and inorganic nitrates. The main idea is to prevent complete nitrogen and phosphorus depletion providing that the product is used according to its dosing instructions. I guess that there are ways of countering some of the disadvantages of organic carbon dosing, which you correctly pointed out in your post. It is possible to have a healthy reef that relies on organic carbon dosing. My system has been relying on it for the past three years. However, I will update this thread if it ever crashes one day.

Happy new year.

PS. The links you provided in your post are not accessible.

Belgian Anthias
01/01/2018, 02:19 PM
Well that made my head feel funny lol. Question though, you keep saying Carbohydrates, do you mean Carbon? Never heard of Carbohydrate dosing.

Organic carbon. What is added to the system are carbohydrates as ethanol (wodka), sucrose (sugar) , acetic acid ( vinegar).

Belgian Anthias
01/01/2018, 03:07 PM
Thanks for sharing your knowledge.

PS. The links you provided in your post are not accessible.

Happy new year!

In that case you must log in or register. Makazi Baharini is a closed dokuwiki.

NP-BACTO-BALANCE: Can not find out how much usable organic carbon it contains. It claims creating an optimal nitrate-phosphate balance. It would be interesting to know how it is able to do so and what this optimal balance should be. For biosynthesis ( assimilation) this would be in weight +- 10 to 1.

DiscusHeckel
01/01/2018, 03:12 PM
Happy new year!

In that case you must log in or register. Makazi Baharini is a closed dokuwiki.

NP-BACTO-BALANCE: Can not find out how much usable organic carbon it contains. It claims creating an optimal nitrate-phosphate balance. It would be interesting to know how it is able to do so and what this optimal balance should be. For biosynthesis ( assimilation) this would be in weight +- 10 to 1.

That's correct. In long term use (just under three years), I have achieved 10:1 ratio.

I was informed by Hans-Werner Balling that Tropic Marin "have chosen a harmless simple organic N compound that releases ammonia after hydrolysis to avoid the potentially dangerous ammonia itself. The organic N compound is quite stable but can be hydrolyzed by enzymes of corals and bacteria quickly."

Belgian Anthias
01/01/2018, 04:03 PM
By providing additional carbohydrates a cycle is created from NH4 to NH4. Only +- 30% of the cultivated biomass will be removed by a skimmer. http://www.baharini.eu/baharini/doku.php?id=en:makazi:het_water:filtratie:eiwitafschuimer. The rest must be consumed. it becomes part of the food cycle.
To reduce 1 g NH4-N, +- 8 g protein is produced, the equivalent of 20 grams food containing 30% protein. When the produced protein is consumed some is used to increase the total bioload but most of it will be released as ammonia and a bit ureum. To reduce 1gram nitrate by assimilation also 0,1gram phosphate is needed. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:ammonium_reductie This may become an issue in biopellet reactors.
Once regular dosing carbohydrates, most of the dose is used to remove ammonia which is the result of previous doses.

It must be clear that when additional carbohydrates are provided this must be taken in account for the total food supply. A refugium can be added to help consume the produced bacterial biomass by organisms which may be used as a food souce.
It must also be clear that when the organic carbon supply is interrupted biomass will decay. Organisms which depend on it will die. On that moment nitrification capacity will be insufficient .

Heterotrop ammonia reduction produces a lot of biomass, 40x more as nitrification. This is done every cycle from NH4 to NH4. It is a fact that +- 2% of the bacterial biomass will be lost as it is not recyclable and will be left as detritus.
The growt may also become an issue when biofilters or DSB are used. They may clog. But at a high maintained C:N ratio these filters are not needed.

DiscusHeckel
01/01/2018, 04:40 PM
It must be clear that when additional carbohydrates are provided this must be taken in account for the total food supply. A refugium can be added to help consume the produced bacterial biomass by organisms which may be used as a food souce.

It must also be clear that when the organic carbon supply is interrupted biomass will decay. Organisms which depend on it will die. On that moment nitrification capacity will be insufficient .



What about increasing the amount of activated carbon already used or even perhaps start to fluidise it to increase its efficiency of adsorption rate of bacterial mass? Activated carbon was shown to be more efficient in removing total dissolved organics than a protein skimmer.

Dan_P
01/01/2018, 04:59 PM
Nitrate assimilation
Nitrate assimilation is subjected to regulation that may differ depending on the organism. In general, nitrate assimilation is controlled at the transcriptional level by nitrate and nitrite induction and by ammonium repression.

Many systems are controlled at this level. No arguement here

In the pre-genome sequence era, it was known that some, but not all, heterotrophic bacteria were capable of growth on nitrate as a sole nitrogen source. However, examination of currently available prokaryotic genome sequences suggests that assimilatory nitrate reductase (Nas) systems are widespread phylogenetically in bacterial and archaeal heterotrophs.
In cyanobacteria, the transcription factor represses nitrate assimilation genes when ammonium is present whereas it activates transcription of these genes at a high carbon/nitrogen ratio.

Without a reference to the study, I will take your word for it, though this seems reasonable. Complementary chromatic adaptation has been described for cyanobacteria and there seems to be a link between color of the organism and nitrogen source. No surprise then about the level of control but the notion that a high C to N ratio is a trigger is interesting. Again, no reference, so, I will take your word for now.

The nitrate-assimilation process begins with the transport of nitrate into the cell. Nitrate is further reduced to nitrite in a two-electron reaction by a cytoplasmic molybdenum containing nitrate reductase followed by a six-electron nitrite reduction to produce ammonia.
The assimilatory reduction of nitrate to ammonium is an energetically expensive process since it requires eight electrons and complex prosthetic groups for the nitrate and nitrite reductase enzymes, in addition to the active nitrate transport. In order to avoid this energetic cost under unnecessary environmental conditions, bacteria have evolved a strict control of the expression of the Nas system. Thus expression of the Nas genes is subjected to dual control based on specific nitrate or nitrite induction, and ammonium repression, by a general nitrogen-regulatory system. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:bio-chemie:nitraat_reductie

Link does not work but this is well known.

When adding carbohydrates for the first time not a lot will change to the nitrate level. Ammonia, normally nitrified by autotrophs, is used first . Only when the supply of ammonia is insufficient nitrate will be used. When dosing is continued nitrification will be suppressed due to ammonia availability as the heterotrophs grow a lot faster. Heterotroph ammonium reduction ( assimilation) produces 40 x more bio mass compared to autotroph ammonia reduction. ( http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:ammonium_reductie )

This is published in the aquaculture literature

As a result less nitrate will be produced. The moment the C:N ratio increases due to dosing and increased ammonium take up ( and less or no nitrate production) nitrate may be used for celsynthesis. Nitrate is also taken up for respiration. Nitrate take up for respiration is not suppressed by ammonia. The nitrate level may be depleted fast at high C:N ratio. All this implements a very low nitrification and denitrification capacity.

The potential risks of robbing Peter to pay Paul does not seem to be addressed in the aquarium carbon dosing discussions. Maybe most aquarists get away with a reduced denitrication capacity. In low nutrient systems like reef aquaria, maybe the risk is not so high.

When biopellets are used in a reactor there is always a high C:N ratio available.

An aquarium system that is kept in balance by carbohydrate dosing has a limited carrying capacity. Such systems are vulnerable for a system crash due to the well known new tank syndrome.
Once started dosing it may be difficult to stop. Dosing should be build off during a period of at least 15 days.

The carbon dosing system vulnerability conjecture needs support. It is reasonable and something that I have wondered about but could be absolutely wrong. Yes, switching back and forth, between non-dosing to dosing or dosing to non-dosing, with minimal accumulation of ammonia or nitrate would take time for the population of organisms to readjust. But to say that one regimen has a higher “carrying capacity” needs support. It might be amenable to an stoichiometric calculation.

bertoni
01/01/2018, 08:23 PM
An aquarium system that is kept in balance by carbohydrate dosing has a limited carrying capacity. Such systems are vulnerable for a system crash due to the well known new tank syndrome.
Once started dosing it may be difficult to stop. Dosing should be build off during a period of at least 15 days.
I don't know of any evidence supporting this statement. A number of people have posted otherwise as far as stopping the dosing, due to the capacity to consume ammonia. Both the carbon-consuming organisms and the standard microbes can grow, given enough ammonia, and they might not overlap physically.

Belgian Anthias
01/02/2018, 02:59 AM
Many systems are controlled at this level. No arguement here



Without a reference to the study, I will take your word for it, though this seems reasonable. Complementary chromatic adaptation has been described for cyanobacteria and there seems to be a link between color of the organism and nitrogen source. No surprise then about the level of control but the notion that a high C to N ratio is a trigger is interesting. Again, no reference, so, I will take your word for now.



Link does not work but this is well known.



This is published in the aquaculture literature



The potential risks of robbing Peter to pay Paul does not seem to be addressed in the aquarium carbon dosing discussions. Maybe most aquarists get away with a reduced denitrication capacity. In low nutrient systems like reef aquaria, maybe the risk is not so high.



The carbon dosing system vulnerability conjecture needs support. It is reasonable and something that I have wondered about but could be absolutely wrong. Yes, switching back and forth, between non-dosing to dosing or dosing to non-dosing, with minimal accumulation of ammonia or nitrate would take time for the population of organisms to readjust. But to say that one regimen has a higher “carrying capacity” needs support. It might be amenable to an stoichiometric calculation.

The links should work. If an access denied page is shown one must register and log in to get access to the wiki. All references are included in the wiki articles and most references can be consulted. The wiki is written in Dutch, some pages are translated in English. Most references used are in English.

In LNS a caveat may be the competition for available phosphate and other building materials certainly when the doses do not correspond the needs.
In LNS the doses may be responsible for most of the biomass production, more as normal feedings. As the small amount ammonia is immediately taken up when it becomes available most LNS do have very little or no nitrification capacity. Not a problem as long as the ammonia take up rate will be maintained.

The "carrying capacity" is the capacity of the system to reduce ammonia. Normally 2/3 is reduced by nitrification.
The "carrying capacity" is decisive for the maximum bioload.
When organic carbon dosing is used to reduce ammonia the carrying capacity is easily adjusted but the system may become completely dependable of these doses and the corresponding bacterial growth which growth is dependable of a lot of other factors and parameters.

Belgian Anthias
01/02/2018, 04:37 AM
I don't know of any evidence supporting this statement. A number of people have posted otherwise as far as stopping the d, due to the capacity to consume ammonia. Both the carbon-consuming organisms and the standard microbes can grow, given enough ammonia, and they might not overlap physically.

Of coarse all bacteria may grow when given enough ammonia and other building materials but when the usable organic carbon is matched the heterotrops will use up most of the ammonia leaving very little or nothing for the nitrifiers and other organisms because of the very high grow rate. This is supported by all approved publications I have read about ammonia reduction in aquaculture systems . http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:ammonium_reductie More evidence I do not need.
In zero emission marine aquaculture systems ( ZMAS) using carbohydrates dosing to maintain a high C:N ratio no or little nitrate is produced.

Which are the standard microbes? Nitrifiers and denitrifiers?
How one can avoid the bacteria to overlap "physically"?

For me It is logic that when ammonia is removed by assimilation this ammonia is not available for nitrification and denitrification. It is a fact that autotrophs are suppressed by heterotroph growth.

Belgian Anthias
01/02/2018, 05:56 AM
It takes about 1 day for heterotrops to double there biomass. it takes about 15 days for autotrophs ( nitrifiers) to double there biomass. This means that at least 15 days are needed to double the nitrifying capacity when for some reason the heterotroph growth can not be maintained and longer to become normal.

All recipes for carbohydrate dosing are based on the nitrate level. But it is not nitrate that triggers the bacterial growth, it is ammonia by priority..

In nature and in aquaria usable organic carbon is limited available. This way making it possible most organic material can be recycled and the nitrogen cycle can be completed. Nitrogen is send back were it came from and is not stored in biomass.
What happens when organic carbon is unlimited available?


In LNS or VLNS dosing must be correct, corresponding to the needs. Otherwise not all of it may be used for growth due to not enough building material. The moment building material as phosphate is delivered the competition for the building material may end up in a real war. Guess who will win!?
In general in LNS where the balance is maintained by carbon dosing a high C:N ratio is available.
Are we going to assume that doses are ok or is there a way to be sure the dosing is correct.?
What do we know about the hierarchy between organisms in using building materials?

Commercial products which contain polymers and other building materials are available but how to dose these products if one thus not know how many organic carbon is actually released or used? Following the guidelines assuming it will be ok?

Biopellets used in a reactor: the carbon source is unlimited available in the reactor but the other building materials are not.

The question asked when biofilters are used for ammonia reduction is:"What to do with the nitrate produced" As nitrogen can easily be removed from the system to where it came from this problem can be solved.

The question asked when carbohydrates are dosed for ammonia reduction may be:"What to do with the biomass produced?"
In aquaculture systems the biomass is harvested and a new batch is started.
When algae scrubbers are used for assimilative ammonia reduction the produced biomass is harvested.

DiscusHeckel
01/02/2018, 06:21 AM
You have not answered my previous question about the use of activated carbon to harvest the produced biomass.

Dan_P
01/02/2018, 06:59 AM
The links should work. If an access denied page is shown one must register and log in to get access to the wiki. All references are included in the wiki articles and most references can be consulted. The wiki is written in Dutch, some pages are translated in English. Most references used are in English.


How do I register? What’s the Dutch word I am looking to click to register?
Maybe you could cut and paste the references into this post so we can at least read the science behind conjectures.

Dan_P
01/02/2018, 07:14 AM
It takes about 1 day for heterotrops to double there biomass. it takes about 15 days for autotrophs ( nitrifiers) to double there biomass. This means that at least 15 days are needed to double the nitrifying capacity when for some reason the heterotroph growth can not be maintained and longer to become normal.

Yes, the heterotrophs can grow quickly, even to the point that they serve as food in shrimp aquaculture.

All recipes for carbohydrate dosing are based on the nitrate level. But it is not nitrate that triggers the bacterial growth, it is ammonia by priority..

I wondered about this. This is probably the explanation for the delay in nitrate reduction when dosing is started.

In nature and in aquaria usable organic carbon is limited available. This way making it possible most organic material can be recycled and the nitrogen cycle can be completed. Nitrogen is send back were it came from and is not stored in biomass.
What happens when organic carbon is unlimited available?

A lot of carbon goes into energy requirements, production of CO2. I think something like more than 50% of the carbon consumed goes to CO2. This is one factor preventing aquaria from turning into sewage plants.

bertoni
01/02/2018, 02:12 PM
For me It is logic that when ammonia is removed by assimilation this ammonia is not available for nitrification and denitrification. It is a fact that autotrophs are suppressed by heterotroph growth.
This has nothing to do with carrying capacity, at least as far as I use the term. Maybe you mean something else, but I take it to mean the upper limit of the ammonia that the tank can process per unit time.

bertoni
01/02/2018, 02:33 PM
IAll recipes for carbohydrate dosing are based on the nitrate level. But it is not nitrate that triggers the bacterial growth, it is ammonia by priority..

I'm not sure why this matters. The end result is the consumption of nitrate, and I think we've all seen that dosing requires per-tank tuning.

bertoni
01/02/2018, 02:34 PM
By providing additional carbohydrates a cycle is created from NH4 to NH4. Only +- 30% of the cultivated biomass will be removed by a skimmer.
I don't see any reason to believe that we know how much of the cultivated biomass will be exported. Clearly, in practice, tanks generally can export as much as is needed. Some tanks certainly have issues with carbon dosing, for reasons that aren't clear.

Dan_P
01/02/2018, 06:22 PM
I'm not sure why this matters. The end result is the consumption of nitrate, and I think we've all seen that dosing requires per-tank tuning.

I am not familiar with how one determines how much carbon to add to an aquarium but for aquaculture, the amount of carbohydrate added is based on the stoichiometric balance of C:N that is required by heterotrophs to assimilate all the nitrogen in the feed. I always assumed that dosing aquaria is more an empirical exercise, starting low and increasing. As you say, per-tank tuning. I will bet no one doses carbon to balance the C:N ratio in what they add to the tank. Would be an interesting experiment though.

As for heterotrophs consuming nitrate because we carbon dose, has this been proven in an aquarium this is what actually happens? Might another explanation be that nitrate production is minimized because of increased ammonia assimilation by hetertrophic bacteria and the nitrate already produced is simply converted to nitrogen by autotrophs?

Dan_P
01/02/2018, 06:37 PM
I don't see any reason to believe that we know how much of the cultivated biomass will be exported. Clearly, in practice, tanks generally can export as much as is needed. Some tanks certainly have issues with carbon dosing, for reasons that aren't clear.

Why don’t we know how much biomass is exported? Even public and commercial aquariums don’t know?

bertoni
01/02/2018, 06:41 PM
As for heterotrophs consuming nitrate because we carbon dose, has this been proven in an aquarium this is what actually happens? Might another explanation be that nitrate production is minimized because of increased ammonia assimilation by hetertrophic bacteria and the nitrate already produced is simply converted to nitrogen by autotrophs?
Interesting point! It's possible that the reduction in the nitrate level is indeed due to decreased nitrate production, resulting in a declining level due to standard denitrification. It'd be hard to be sure what's happening, but I'll be more careful in my wording in the future.

bertoni
01/02/2018, 06:48 PM
Why don’t we know how much biomass is exported? Even public and commercial aquariums don’t know?
I don't know of any way to measure it, in practice. It can leave the tank (or nutrient flow, at least) in a number of ways. The various components of the biomass can be skimmed or be exported via water changes, denitrification, outgassed as carbon dioxide, or deposited as phosphate, etc, in coral skeletons or coralline. The last case isn't technically export from the system, but it does remove the nutrients from the nutrient flow in the tank, at least for some period of time.

A lot of things can be skimmed, and characterizing what comes out of the skimmer back into what was in the tank would be non-trivial, in my opinion. One guess is that carbon dosing removes nutrients by feeding bacteria that release skimmable organics. It's also likely that at least some of the carbon is consumed by bacteria that are themselves skimmed, but I don't know how much that would be.

Dan_P
01/02/2018, 07:15 PM
, but I'll be more careful in my wording in the future.

Me too.

Dan_P
01/02/2018, 07:26 PM
denitrification, outgassed as carbon dioxide, or deposited as phosphate, etc,

Maybe the determination is along the lines of measuring the metabolic rate of animals but do it for the entire aquarium. This feels like a serious Google research project.

bertoni
01/02/2018, 07:40 PM
Of coarse all bacteria may grow when given enough ammonia and other building materials but when the usable organic carbon is matched the heterotrops will use up most of the ammonia leaving very little or nothing for the nitrifiers and other organisms because of the very high grow rate. This is supported by all approved publications I have read about ammonia reduction in aquaculture systems .
That's probably true, but I don't see the relevance.

Which are the standard microbes? Nitrifiers and denitrifiers?
How one can avoid the bacteria to overlap "physically"?
By inhabiting difference parts of the live rock, or by growing in the water column, as beginning examples. Denitrification has been posited to happen more in pores than on lit surfaces, for example. Heterotrophic consumption might be less restricted (or not).

For me It is logic that when ammonia is removed by assimilation this ammonia is not available for nitrification and denitrification. It is a fact that autotrophs are suppressed by heterotroph growth.
Again, likely true, but irrelevant to this discussion.

Belgian Anthias
01/03/2018, 02:02 AM
I'm not sure why this matters. The end result is the consumption of nitrate, and I think we've all seen that dosing requires per-tank tuning.

If it does not matter?!
The end result is possibly a tank that may have no nitrification capacity at all. A full active and populated tank with the same nitrification and denitrification capacity as a new tank may be the result. Is the possibility that this situation may be created insignificant or neglect able ? For me this problem is a decision maker and solving it a priority before I would take the risk for dosing carbohydrates.
My opinion the doses should be based in function of the C:N ratio . But how this can be done?
How can one "fine tune" carbon dosing based on the nitrate concentration without taking the risk bringing the tank in a dangerous situation and this to "fine tune" something that is no threat and certainly not dangerous for the tank at all.?

Belgian Anthias
01/03/2018, 03:10 AM
That's probably true, but I don't see the relevance.

By inhabiting difference parts of the live rock, or by growing in the water column, as beginning examples. Denitrification has been posited to happen more in pores than on lit surfaces, for example. Heterotrophic consumption might be less restricted (or not).


Again, likely true, but irrelevant to this discussion.

No relevance to this discussion?
This discussion is about assimilative ammonia and assimilative nitrate reduction and about the ammonia reduction rate which makes out the carrying capacity of each system. Nitrate by itself is not a concern at all in this discussion.

The carrying capacity and the calculation of the max bioload is explained in a publication of Spotte, S., 1979. Fish and invertebrate culture: water management in closed systems, 2d ed. ed. Wiley, New York. This is relevant lecture ! Basics for managing an aquarium.


How denitrifiers can install when there is no or little nitrate produced due to maintaining a high C:N ratio.?
Nitrate is a key factor for a healthy biofilm as it is used for recycling the biomass within any biofilm for oxidizing the produced HS. http://www.baharini.eu/baharini/doku.php?id=en:makazi:bio-chemie:biofilm#the_study_of_the_biofilm
Assimilative heterotrophs grow on the surface of a biofilm and in the water column and will influence the biological balance all over the system as they are the main oxygen and building material consumers due to the very high growth rate. Carbon dosing effects all organisms directly or indirectly.
Carbon dosing will prevent the construction of balanced mixotrophe biofilms.
Live rock is a biofilter with a low capacity, certainly when high a C/N ratio is maintained as the pores will clog. Anyway, if a high C:N ratio is maintained the function of live rock and other biofilters is bypassed as no or little nitrate will be produced.

Belgian Anthias
01/03/2018, 04:28 AM
How do I register? What’s the Dutch word I am looking to click to register?
Maybe you could cut and paste the references into this post so we can at least read the science behind conjectures.



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Belgian Anthias
01/03/2018, 05:04 AM
You have not answered my previous question about the use of activated carbon to harvest the produced biomass.

It will certainly help reducing TOC and DOC.
In fact better as a skimmer as it is known that a skimmer removes max 35% of TOC. Not skim able TOC will stay behind and build up, skim able TOC is removed. Bacteria are forced to use not skim able DOC.
The use off skimmers is in discussion because of the selective way they feed and remove live bacteria and the effect on the bacterial balance and evolution on the long term in a closed environment. It would be interesting to know which strains are skimmed and which strains are not skimmed. Which strains are favoured by not skim able DOC. In fact, most live bacteria removed are not skimmed but carried out on the foam. http://www.baharini.eu/baharini/doku.php?id=en:makazi:het_water:filtratie:eiwitafschuimer.
The use of skimmers is an other discussion.

Activated carbon will not prevent that the produced protein due to carbon dosing will be consumed and become part of the food chain. As far as I know it does not absorb life bacteria ( with the exception of those which grow on it the moment it is removed).

Belgian Anthias
01/03/2018, 05:50 AM
I

A lot of things can be skimmed, and characterizing what comes out of the skimmer back into what was in the tank would be non-trivial, in my opinion. One guess is that carbon dosing removes nutrients by feeding bacteria that release skimmable organics. It's also likely that at least some of the carbon is consumed by bacteria that are themselves skimmed, but I don't know how much that would be.

This has been part of a research project of the University of Pennsylvania by Ken S. Feldman, Kelly M. Maers. Department of Chemistry, The Pennsylvania State University, University Park, PA 16802.
So no complete guess work any more as we have results. The organics removed are included in the 35% which was determined to be the maximum TOC removed by a skimmer. They concluded that concerning skimmers there is more difference in price as there is difference in the ability to remove TOC and DOC. Skimmers are very selective in removing live bacteria, some strains are removed, some are not. Most are not skimmed but carried out on the foam. http://www.baharini.eu/baharini/doku.php?id=en:makazi:het_water:filtratie:eiwitafschuimer

Dan_P
01/03/2018, 11:50 AM
On the Dutch page "Toegang geweigerd" below the login button you will find the Dutch word "Registreren"

When you use this link: http://www.baharini.eu/baharin/doku.php?id=en:makazi:het_water:filtratie:eiwitafschuimer the access denied page is not shown as this page is made public for the moment. In the left side upper corner of the page you find a login button to register in English

When a link is used containig id=en: for example http://www.baharini.eu/baharini/doku.php?id=en:makazi:bio-chemie:biofilm the access denied page is in English.

Once registered you will receive a login in your mailbox

We have to do it this way to protect the rights of the authors as most references used are consult able for private use only and the content may not be published without respecting the publishing rights on the article or paper. If content of the wiki is used for publication on the web one must refer to the article with a link to the page in question. Content of consult able references may only be used for publication with the permission of the authors or/and publisher of the publication.

In the left upper corner of each wiki page one can switch languages.

it is possible to use the wiki for your own articles.


I am in! Thanks very much! Connecting with information and ideas is the reason I find this site so useful and interesting.

Everyone else on this thread might want to register and read the information first hand. Enough is in English to get some useful information.

bertoni
01/03/2018, 02:25 PM
If it does not matter?!
The end result is possibly a tank that may have no nitrification capacity at all. A full active and populated tank with the same nitrification and denitrification capacity as a new tank may be the result. Is the possibility that this situation may be created insignificant or neglect able ? For me this problem is a decision maker and solving it a priority before I would take the risk for dosing carbohydrates.
My opinion the doses should be based in function of the C:N ratio . But how this can be done?
How can one "fine tune" carbon dosing based on the nitrate concentration without taking the risk bringing the tank in a dangerous situation and this to "fine tune" something that is no threat and certainly not dangerous for the tank at all.?
I don't understand what you are saying here. As long as the nitrate level is acceptable, whether the level is maintained by denitrification or by carbon dosing seems irrelevant. Tuning the dose (the carbon input) to match the nitrate imported via food requires some trial and error, but doesn't seem to be a significant problem.

bertoni
01/03/2018, 02:53 PM
No relevance to this discussion?
This discussion is about assimilative ammonia and assimilative nitrate reduction and about the ammonia reduction rate which makes out the carrying capacity of each system. Nitrate by itself is not a concern at all in this discussion.

The carrying capacity and the calculation of the max bioload is explained in a publication of Spotte, S., 1979. Fish and invertebrate culture: water management in closed systems, 2d ed. ed. Wiley, New York. This is relevant lecture ! Basics for managing an aquarium.


How denitrifiers can install when there is no or little nitrate produced due to maintaining a high C:N ratio.?
Nitrate is a key factor for a healthy biofilm as it is used for recycling the biomass within any biofilm for oxidizing the produced HS. http://www.baharini.eu/baharini/doku.php?id=en:makazi:bio-chemie:biofilm#the_study_of_the_biofilm
Assimilative heterotrophs grow on the surface of a biofilm and in the water column and will influence the biological balance all over the system as they are the main oxygen and building material consumers due to the very high growth rate. Carbon dosing effects all organisms directly or indirectly.
Carbon dosing will prevent the construction of balanced mixotrophe biofilms.
Live rock is a biofilter with a low capacity, certainly when high a C/N ratio is maintained as the pores will clog. Anyway, if a high C:N ratio is maintained the function of live rock and other biofilters is bypassed as no or little nitrate will be produced.
I don't see the relevance of this information. Whether nitrate is produced or not doesn't seem relevant to me. As long as the basic parameters are acceptable, the fish and corals should be fine.

bertoni
01/03/2018, 02:54 PM
This has been part of a research project of the University of Pennsylvania by Ken S. Feldman, Kelly M. Maers. Department of Chemistry, The Pennsylvania State University, University Park, PA 16802.
So no complete guess work any more as we have results. The organics removed are included in the 35% which was determined to be the maximum TOC removed by a skimmer. They concluded that concerning skimmers there is more difference in price as there is difference in the ability to remove TOC and DOC. Skimmers are very selective in removing live bacteria, some strains are removed, some are not. Most are not skimmed but carried out on the foam. http://www.baharini.eu/baharini/doku.php?id=en:makazi:het_water:filtratie:eiwitafschuimer
You've posted that paper before. I still don't understand the relevance. What are you trying to say?

Dan_P
01/03/2018, 05:18 PM
1) “All this implements a very low nitrification and denitrification capacity.”

2) “An aquarium system that is kept in balance by carbohydrate dosing has a limited carrying capacity. Such systems are vulnerable for a system crash due to the well known new tank syndrome.”

3) “Once started dosing it may be difficult to stop”

I think the above three statements are the key proposals or conjectures concerning carbon dosing.

I have wondered to what extent carbon dosing diminishes our normal or assumed normal nitrification-denitrification system. I think a genomic survey during the start up of carbon dosing would need to be conducted to look for the population shift in bacterial species to address this hypothesis. The literature I have come across would seem to suggest that one could expect an impact on the nitrification-denitrification system.

The second conjecture is of a quantitative nature which I assume refers to a system’s ammonia removal capability, or is it the nitrate removal capability? The claim of an increase risk of a system crash is new to me. Also, system crash is a hobby term that is loosely defined. New tank syndrome, or bad beginner’s luck, is also too broadly used. But if system crash and new tank syndrome refers to high ammonia concentration, then I would ask where is the data of carbon dosing causing ammonia spikes. Anyway, the proposal needs clarification.

Finally, the third proposal might be derivative of the aphorism “never change or do anything quickly to an aquarium”. Has anyone suddenly stopped dosing carbon and observed what happens? Maybe not.

Good discussion so far.

Dan

bertoni
01/03/2018, 05:43 PM
If my memory is correct, a number of people have reported stopping carbon dosing without tapering off, but I might be mistaken. If I get some time, I'll try to search some.

Benar
01/03/2018, 06:11 PM
Would this be why KZ/Zeovit requires zeolite ammonia adsorbant & carbon. Also why they add nitrate to their carbon source have anything to do with it all?


Sent from my iPhone using Tapatalk

bertoni
01/03/2018, 07:27 PM
I think the zeolite acts as artificial live rock or a bacterial substrate of some sort over the long term. It won't adsorb ammonia indefinitely unless the ammonia is consumed in some way.

Adding nitrate to the carbon source would allow the product to remove phosphate from the water column after fixed nitrogen has become limiting. Maybe their guess is that most tanks will be nitrogen-limited before enough phosphate has been removed.

Belgian Anthias
01/04/2018, 03:24 AM
A lot of heterotrops and autotrophs ( denitrifiers) have also or only a transport system for nitrate take up for respiration. This respiratory Nar system is triggered by nitrate, suppressed by oxygen and is not sensitive for ammonia. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:bio-chemie:nitraat_reductie

In most normal biofilms surrounded by oxygen saturated seawater denitrification takes place. Oxygen is consumed in the outer layers of the film in a way not enough oxygen can reach the middle and lower zones . In normal circumstances, about 1/3 of the oxygen is used by heterotrops and 2/3 for nitrification, +- 1/3 of the ammonia is reduced by heterotrops and +-2/3 by autotrops.
An oxygen minimum zone ( OMZ) is created within the film, ideal for autotrophe denitrification. The Nar system of autotrop denitrifiers may be triggered at an oxygen level above 0,5 ppm. Autotroph denitrification is limited because of the limited availability of usable sulphur provided by HS production within the film. This limited autotrop denitrification is necessary for recycling HS formed due to decay within the film, back to sulphur or sulphate. In the sub layers anoxic conditions may be created and heterotroph denitrification may be activated. Most heterotrophs need an oxygen level lower as 0,5 ppm to trigger the Nar system. The heterotroph denitrification is limited by the available organic carbon provided by normal decay within the biofilm and the limited anoxic space. http://www.baharini.eu/baharini/doku.php?id=en:makazi:bio-chemie:biofilm

When a high C:N ratio is maintained by carbohydrate dosing most ammonia is assimilated in the water column but also in the biofilm. The structure of the biofilm will change drastically as the nitrifiers are overgrown by the very fast growing heterotrops and lose the battle for oxygen. As the nitrifiers are suppressed the ammonia they normally use is available for assimilation. Due to the very high growth and oxygen consumption in and on the outer layers of the film the OMZ zone may become anoxic making more heterotroph denitrification possible. When not enough nitrate is available, sulphate will be used.
After some time the biodilm will become mostly heterotropic due to the competition for nitrate in the low oxygen zone and the high decay rate providing organics. HS will not be recycled any more within the biofilm but oxidised when leaving the biofilm producing sulphate.
Autotrophs are outcompeted! The autotrophic ammonia reduction potential which was build up is lost.

An other biologic balance will be found and the heterotroph growth may be matched to keep this balance by maintaining a balancing C:N ratio. This means regular and continues dosing.

More nitrate may be removed effectively from the system by increased heterotroph denitrification.

Keeping a low slightly increased C:N ratio may induce a higher mixotroph denitrification rate within a normal nitrifying biofilm. This can also be done by providing some more usable sulphur to the biofilm , this way eliminating daily matched dosing. http://www.baharini.eu/baharini/doku.php?id=en:badess:bades_bio_filter#spc_system

For a biofilm in a very low oxygen environment ( live rock, DSB) this scenario may be a bit different. HS can not be oxidised when leaving the biofilm, may build up and be released as H2S gas.

Belgian Anthias
01/04/2018, 04:57 AM
I don't understand what you are saying here. As long as the nitrate level is acceptable, whether the level is maintained by denitrification or by carbon dosing seems irrelevant. Tuning the dose (the carbon input) to match the nitrate imported via food requires some trial and error, but doesn't seem to be a significant problem.

The way it is done is irrelevant?

When nitrate is denitrified NO3-N is removed from the system and the carrying capacity, the ability of the system to remove ammonia, of the system is maintained at all times even when denitrification is interrupted or stopped for a period of time.

When nitrate must be assimilated first all NH4-N must be assimilated into biomass, than NO3-N may be used. As there is insufficient ammonia availability for nitrification no or little nitrate is produced and the nitrifying capacity is drastically reduced or stopped. The carrying capacity of the system, the ability to remove ammonia, may depend largely or completely on dosing. When dosing is interrupted or stopped the system needs time to reinstall sufficient autotrophic carrying capacity bringing the system in an unbalanced and possible very dangerous situation.
Most nitrogen is not removed but taken into a not ending cycle within the closed environment of the aquarium.

Leaves the other pro's and con's of both complete different applications.

Belgian Anthias
01/04/2018, 05:40 AM
You've posted that paper before. I still don't understand the relevance. What are you trying to say?

As a lot of users think that a skimmer removes the biomass produced by carbon dosing the limited ability to remove biomass by skimmers is more than relevant.

Belgian Anthias
01/04/2018, 05:50 AM
"What to do with the continually increasing biomass " is one of the problems to solve.

If one is able to complete the food chain one can introduce some Litopenaeus vannamei,in a refuge which will be harvested when big enough to be consumed. This way nothing is lost.:spin2:

bertoni
01/04/2018, 02:20 PM
The way it is done is irrelevant?

That's my opinion.
When dosing is interrupted or stopped the system needs time to reinstall sufficient autotrophic carrying capacity bringing the system in an unbalanced and possible very dangerous situation.
The system might or might not require much time to recover an ammonia-processing capacity. I don't see why this is relevant. If you're worried, just back off slowly on carbon dosing. That's what I generally recommend.

I'm not sure what you mean by "unbalanced". Balanced with respect to what? I also disagree about carbon dosing being particularly dangerous. I haven't seen any evidence of that since the dosing guidelines were created.

bertoni
01/04/2018, 02:22 PM
As a lot of users think that a skimmer removes the biomass produced by carbon dosing the limited ability to remove biomass by skimmers is more than relevant.
The paper covers the effectiveness of skimming in one set of circumstances. I am not sure how this situation applies directly to carbon dosing.
"What to do with the continually increasing biomass " is one of the problems to solve.
I see no evidence of a continually increasing biomass due to carbon dosing, nor do I understand how that could happen.

Dan_P
01/04/2018, 07:27 PM
I see no evidence of a continually increasing biomass due to carbon dosing, nor do I understand how that could happen.

I think the notion is that the carbon being dosed induces a growing number of bacteria. To assimilate nitrogen and phosphorous, bacterial biomass must increase. If the number of bacteria aren’t increasing, the uptake of nitrogen and phosphorous will not be as high. I don’t have a feeling for how long a bacterium that isn’t dividing exists and if it does “just” live, how much material it needs to just hang around.

Where things get really fuzzy for me in this discussion is the rate of biomass accumulation in an aquarium, say for every gram of food you add to the tank. First, a lot of carbon is consumed for energy needs with CO2 given off. More than 50% I believe. What isn’t eaten by the fish is consumed by bacteria, protozoa, fungus, etc. When bacterial biomass is eaten, more than half that carbon goes to CO2. When whatever ate the bacterium is eaten, half of that carbon goes to CO2. Carbon, and biomass, leave the aquarium as you move up the food chain. Do we know at what point that it accumulates at an unhealthy level? Is that point different for every system?

Nitrogen added to the aquarium by food either goes to either biomass or waste (N2, NH3, NO3, slowly metabolized organic nitrogen compounds). Changing the ratio of C:N in the food or by carbon dosing means shifting wasted nitrogen to biomass nitrogen. But at what point does this biomass derived from food need to be harvested. I suppose if bacterial biomass grows quicker than predation reduces it, you grow a visible slime. Or if the nitrogen level becomes too low to support a large population of bacteria that was created by carbon dosing, I guess the bacterial population declines or crashes, maybe releasing waste back into the aquarium. In either case, you would have needed to harvest bacterial biomass more aggressively. Still trying to wrap my head around what you would need to know to calculate this. I need to review the notion of bioload and see how other life forms are considered in estimating bioload limits.

Enjoying the insights.

Dan

bertoni
01/04/2018, 08:04 PM
I think the notion is that the carbon being dosed induces a growing number of bacteria. To assimilate nitrogen and phosphorous, bacterial biomass must increase. If the number of bacteria aren’t increasing, the uptake of nitrogen and phosphorous will not be as high. I don’t have a feeling for how long a bacterium that isn’t dividing exists and if it does “just” live, how much material it needs to just hang around.
I agree that creating more net biomass is likely to consume nitrogen and phosphorus at a higher rate than other consumption patterns. That said, a lower consumption rate might be fine. Whether a tank takes an hour to consume a daily dose of vinegar or 12 hours, either way, nitrogen and phosphorus seem to be converted to a skimmable form in some tanks, from what we can see. The biomass must stop increasing at some point, or the tank would be filled (literally) with bacteria, but that does not imply that export stops, or won't be effective. For all we know, dying bacteria or their remains might be highly skimmable.

Where things get really fuzzy for me in this discussion is the rate of biomass accumulation in an aquarium, say for every gram of food you add to the tank. First, a lot of carbon is consumed for energy needs with CO2 given off. More than 50% I believe. What isn’t eaten by the fish is consumed by bacteria, protozoa, fungus, etc. When bacterial biomass is eaten, more than half that carbon goes to CO2. When whatever ate the bacterium is eaten, half of that carbon goes to CO2. Carbon, and biomass, leave the aquarium as you move up the food chain. Do we know at what point that it accumulates at an unhealthy level? Is that point different for every system?
I certainly agree that we don't know much about the rate of biomass increase in our tanks. As far as bad effects of carbon dosing, in some cases, tanks seem to suffer from bacterial slimes or even cloudy water. I don't know whether those cases truly are dangerous, or just esthetic, but I tend towards caution when giving recommendations.

Of course, some bacteria might produce problematic or even toxic compounds. In addition, increasing the total organic load in the tank might cause problems. Some tanks might have issues of this type, which is why I tend to encourage a slow increase in the carbon dose. Even so, most problems seem to be starving corals, rather than organics. We lack useful tools to be sure what's happening, though. The same issue can occur in tanks without carbon dosing, as well.

Nitrogen added to the aquarium by food either goes to either biomass or waste (N2, NH3, NO3, slowly metabolized organic nitrogen compounds). Changing the ratio of C:N in the food or by carbon dosing means shifting wasted nitrogen to biomass nitrogen. But at what point does this biomass derived from food need to be harvested.
"Harvesting" is a bit ambiguous here. If you mean direct harvesting by the person or persons running the tank, I doubt that there's any need to do so unless the owner prefers, for example, to run with a growing slime mass and siphoning it from the system. I haven't seen any signs that active harvesting is required. I agree that some set of organisms or viruses are consuming at least some or even most of the bacteria, but I don't know how to quantify that. Direct skimming might remove some bacteria directly, for example.

I suppose if bacterial biomass grows quicker than predation reduces it, you grow a visible slime. Or if the nitrogen level becomes too low to support a large population of bacteria that was created by carbon dosing, I guess the bacterial population declines or crashes, maybe releasing waste back into the aquarium. In either case, you would have needed to harvest bacterial biomass more aggressively. Still trying to wrap my head around what you would need to know to calculate this. I need to review the notion of bioload and see how other life forms are considered in estimating bioload limits.
I agree that a visible slime is one possibility. I'm not so sure that bacterial crashes are going to be a significant danger. Bacterial populations can increase quite rapidly, generally, so I'd expect that a crash would be undetectable with hobbyist equipment. Stopping feeding seldom seems to cause issues, for example, and it's actually a step that I often recommend when dealing with various nutrient buildup or tank crash situations.

Dan_P
01/04/2018, 08:42 PM
I agree that creating more net biomass is likely to consume nitrogen and phosphorus at a higher rate than other consumption patterns. That said, a lower consumption rate might be fine. Whether a tank takes an hour to consume a daily dose of vinegar or 12 hours, either way, nitrogen and phosphorus seem to be converted to a skimmable form in some tanks, from what we can see. The biomass must stop increasing at some point, or the tank would be filled (literally) with bacteria, but that does not imply that export stops, or won't be effective. For all we know, dying bacteria or their remains might be highly skimmable.

Isn’t the notion of carbon dosing essentially growing bacteria? And if so, the rate of increase of a bacterial population depends on conditions, in this case, increasing carbon increases bacterial biomass (I wonder if one gram of carbon results in some tenths of a gram of bacteria. Sounds like too much, there is predation and export as you point out.). And you are right, we typically don’t fill our aquarium with bacteria, though that would be an interesting calculation. 40 gallons of bacteria equals how much vodka. However, when the nitrogen or phosphorous is used up, I am pretty sure the larger bacterial population has few choices if any but to die or form spores. I think to move forwards at this point we need to answer the question how many bacteria are generated from a mg of NH3. I don’t know off hand what a typical bacterial stoichiometric ratio of elements is but assume 5% by weight is nitrogen. That gives 20 milligrams dry weight of bacteria. Spread throughout the aquarium that amount would be invisible, yes? And if skimmable, I would guess removed or diminished in number quite easily. There must be a portion lost through predation too.


"Harvesting" is a bit ambiguous here.
I have macro algae on the brain


I agree that a visible slime is one possibility. I'm not so sure that bacterial crashes are going to be a significant danger. Bacterial populations can increase quite rapidly, generally, so I'd expect that a crash would be undetectable with hobbyist equipment. Stopping feeding seldom seems to cause issues, for example, and it's actually a step that I often recommend when dealing with various nutrient buildup or tank crash situations.

If one suddenly stops dosing carbon and there is no ammonia spike, you have not killed off or severely impacted the system’s ammonia processing capability, i.e., no crash, right?

So where are we? Carbon dosing could impact autotrophs but we have little or no data to say this is a large downside. In principle, we should remove the extra bacteria we grow with carbon dosing to maximize nutrient export but this might not be totally necessary if that bacterial biomass is assimilated and locked up long term in some other biomass, e.g., the tanks population of protozoa, rotifers, amphipods, etc. Are we done here?

bertoni
01/04/2018, 09:39 PM
Isn’t the notion of carbon dosing essentially growing bacteria?
Well, that depends on what you mean... :) The stated goal is to export phosphorus and nitrogen from the system by consuming them from the water column, and then out of the tank via the skimmer. That process could be accomplished by growing a fairly steady bacteria population that exports nutrients via skimming byproduct and the inevitable death and replacement rate, at least in theory. So a net increase of bacterial mass might not be required. Given that some people report dosing carbon for years, it's fairly clear to me that the tank reaches a relative steady state, possibly fairly quickly. Of course, export by skimming the bacteria themselves probably happens to at least some extent. I don't know of anyone who has surveyed the change in bacterial levels in the skimmate with carbon dosing, not over a long time frame, anyway.

And if so, the rate of increase of a bacterial population depends on conditions, in this case, increasing carbon increases bacterial biomass (I wonder if one gram of carbon results in some tenths of a gram of bacteria. Sounds like too much, there is predation and export as you point out.). And you are right, we typically don’t fill our aquarium with bacteria, though that would be an interesting calculation. 40 gallons of bacteria equals how much vodka. However, when the nitrogen or phosphorous is used up, I am pretty sure the larger bacterial population has few choices if any but to die or form spores. I think to move forwards at this point we need to answer the question how many bacteria are generated from a mg of NH3. I don’t know off hand what a typical bacterial stoichiometric ratio of elements is but assume 5% by weight is nitrogen. That gives 20 milligrams dry weight of bacteria. Spread throughout the aquarium that amount would be invisible, yes? And if skimmable, I would guess removed or diminished in number quite easily. There must be a portion lost through predation too.
All interesting points. I personally would guess that there's a lot of mortality in the bacterial population. Viruses and other microbes are happy to kill or consume bacteria. If my memory is correct, the ocean has more viruses looking to infect bacteria than it has bacteria to infect. Our tanks might be similar.

If one suddenly stops dosing carbon and there is no ammonia spike, you have not killed off or severely impacted the system’s ammonia processing capability, i.e., no crash, right?
That's possible. In addition, the ammonia-processing capacity might increase very rapidly in response to the input. At some point, we'll be arguing over wording here. The end result is the same.

So where are we? Carbon dosing could impact autotrophs but we have little or no data to say this is a large downside. In principle, we should remove the extra bacteria we grow with carbon dosing to maximize nutrient export but this might not be totally necessary if that bacterial biomass is assimilated and locked up long term in some other biomass, e.g., the tanks population of protozoa, rotifers, amphipods, etc. Are we done here?
I am sure that carbon dosing will have some impact on autotrophs. I am skeptical about the downside being significant, given the experiences reported here. I think we're done, pending data on what is happening. That data is going to be very expensive to produce, I'd guess, which is too bad. It'd be interesting to see what's happening.

Dan_P
01/05/2018, 09:36 AM
Well, that depends on what you mean... :) The stated goal is to export phosphorus and nitrogen from the system by consuming them from the water column, and then out of the tank via the skimmer. That process could be accomplished by growing a fairly steady bacteria population that exports nutrients via skimming byproduct and the inevitable death and replacement rate, at least in theory. So a net increase of bacterial mass might not be required. Given that some people report dosing carbon for years, it's fairly clear to me that the tank reaches a relative steady state, possibly fairly quickly. Of course, export by skimming the bacteria themselves probably happens to at least some extent. I don't know of anyone who has surveyed the change in bacterial levels in the skimmate with carbon dosing, not over a long time frame, anyway.

This seems like a reasonable high level description. I wonder if what you are feeding by carbon dosing takes over ammonia capture and export from the ammonia oxidizers-denitrifying system.

I would wager that the steady state that you posit above is reached when the ratio of carbon added to the food nitrogen added is at the correct ratio to favor near complete assimilation with little or no waste ammonia to be oxidized to nitrate. This is Belgian Anthias’ point. And when there is a reduced amount of nitrate, then maybe the denitrifying bacteria population is decreased, another Belgian Anthias point.

I have a fish only system with a lot of macro algae but periodic outbreaks of unsightly things (diatoms, cyanobacteria, dinoflagellates all ID’d under a microscope) BUT phosphates are usually undetectable and nitrates less than 0.5 ppm except for occassional unexplained short term nitrate spikes. PO4 and NO3 are poor perdictors of nuissance organism growth. So, I am wondering now based on this debate whether shifts in ammonia production-consumption might be a useful predictor, though impossible for me to measure. I might just try carbon dosing based of nitrogen input to see if the periodic nuissance growth goes away.

Dan

bertoni
01/05/2018, 04:12 PM
I absolutely agree that it's possible that the nitrifying and denitrifying bacteria to be impacted, but I don't see any evidence that this is dangerous. At this point, there are a lot of tanks running with carbon dosing.

I'd like to know what actually happens to the organic carbon and the nitrifying-denitrifying microbes, but I don't see a reasonable way to get that information. I might be wrong, but that seems to be an expensive proposition.

Belgian Anthias
01/07/2018, 08:19 AM
That's my opinion.

The system might or might not require much time to recover an ammonia-processing capacity. I don't see why this is relevant. If you're worried, just back off slowly on carbon dosing. That's what I generally recommend.

I'm not sure what you mean by "unbalanced". Balanced with respect to what? I also disagree about carbon dosing being particularly dangerous. I haven't seen any evidence of that since the dosing guidelines were created.

If it was that simple we would not have this discussion.
Is removing the normal nitrogen cycle which was installed and replace it by an other without risk? May be. May be not? For me it is not a good idea, the reason why I have explained.

Belgian Anthias
01/07/2018, 11:35 AM
increasing carbon increases bacterial biomass (I wonder if one gram of carbon results in some tenths of a gram of bacteria. Sounds like too much, there is predation and export as you point out.). And you are right, we typically don’t fill our aquarium with bacteria, though that would be an interesting calculation. 40 gallons of bacteria equals how much vodka. However, when the nitrogen or phosphorous is used up, I am pretty sure the larger bacterial population has few choices if any but to die or form spores. I think to move forwards at this point we need to answer the question how many bacteria are generated from a mg of NH3. I don’t know off hand what a typical bacterial stoichiometric ratio of elements is but assume 5% by weight is nitrogen. That gives 20 milligrams dry weight of bacteria. Spread throughout the aquarium that amount would be invisible, yes? And if skimmable, I would guess removed or diminished in number quite easily. There must be a portion lost through predation too.

I have macro algae on the brain

So where are we? Carbon dosing could impact autotrophs but we have little or no data to say this is a large downside. In principle, we should remove the extra bacteria we grow with carbon dosing to maximize nutrient export but this might not be totally necessary if that bacterial biomass is assimilated and locked up long term in some other biomass, e.g., the tanks population of protozoa, rotifers, amphipods, etc. Are we done here?

For removing 1 gram of NH4-N by assimilation into biomass 8 grams of protein VSS must be produced. http://www.baharini.eu/baharini /doku.php?id=nl:makazi:het_water:ammonium_reductie +- 4 gram carbon is needed to remove 1 gram NH4-N. +- Half the weight of VSS is carbon. 8 grams of bacterial protein corresponds to approximately 35,2 grams of bacteria. Not included the weight of the reserves stored in vacuoles. 1 gram carbon may be responsible for +- 9 gram bacteria.
400 grams bacteria contain 300 gram water and 100 gram dry material (TSS). TSS consits of 90 gram organic material (VSS) and 10 gram minerals. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:bio-chemie:bacteri%C3%ABn

In fact the only thing we add is the carbohydrate as the rest is provided by the system and feeding.

All approved data to prove my point is available in de Makazi Baharini wiki.

Every link in the food chain will use +- 10 % of the consumed protein and release the rest, most of it as ammonia and ureum. In the case of scrimp as an end user 90% is released back into the system the same day. Some will be used to produce energy the rest will be released when the scrimp dies. To remove something the scrimp must be harvested.

The increase in biomass I do not see as a real problem as this is easily compensated for by the feeding's.

The use of fotoautotrophic ammonia reduction is in my opinion the best way to reduce ammonia and nitrate. A problem may be that +-200 grams of algae must be harvested daily to remove 1 gram NH4-N daily ( 1ppm in a 1000l aquarium)

An other way is increasing the denitrification rate.

Belgian Anthias
01/07/2018, 11:54 AM
I absolutely agree that it's possible that the nitrifying and denitrifying bacteria to be impacted, but I don't see any evidence that this is dangerous. At this point, there are a lot of tanks running with carbon dosing.

I'd like to know what actually happens to the organic carbon and the nitrifying-denitrifying microbes, but I don't see a reasonable way to get that information. I might be wrong, but that seems to be an expensive proposition.

Did you find any evidence that it is not dangerous? That the situation in which a system may be brought due to carbohydrate dosing which I have described is not possible?

Where all this users properly informed and advised about the pro's and con's involved?

All information can be found in the links published by me in this threat. All information is based on approved references which can be consulted with one click. Most is thoroughly explained in this threat.

Belgian Anthias
01/07/2018, 01:27 PM
That's possible. In addition, the ammonia-processing capacity might increase very rapidly in response to the input. At some point, we'll be arguing over wording here. The end result is the same.

I am sure that carbon dosing will have some impact on autotrophs. I am skeptical about the downside being significant, given the experiences reported here. I think we're done, pending data on what is happening. That data is going to be very expensive to produce, I'd guess, which is too bad. It'd be interesting to see what's happening.

How the the ammonia-processing capacity might increase very rapidly in response to the input when carbo dosing is stopped?
The only way to do so is stop feeding which is advisable.
It is a fact that autotroph nitrifiers need 15 days to double there nitrification capacity. If this capacity is brought back to 15 % instead of 60% because of carbo dosing it will take one month to reach the normal capacity needed.

All data is available as heterotrophic ammonia and nitrate reduction has been researched thoroughly during past decennia in university's all over the world. I have used research of Ebeling, J.M., Timmons, M.B., Bisogni, J.J., 2006. (Engineering analysis of the stoichiometry of photoautotrophic, autotrophic, and heterotrophic removal of ammonia–nitrogen in aquaculture systems. Aquaculture 257, 346–358. https://doi.org/10.1016/j.aquaculture.2006.03.019)
to help develop my point of view. The publication can be consulted http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:ammonium_reductie

The suppression of autotrophs by heterotrophs is a key factor in managing mixotropic biofilters and part of most studies about this subject. I advice to read some of these studies.

Dan_P
01/07/2018, 03:15 PM
All data is available as heterotrophic ammonia and nitrate reduction has been researched thoroughly during past decennia in university's all over the world. I have used research of Ebeling, J.M., Timmons, M.B., Bisogni, J.J., 2006. (Engineering analysis of the stoichiometry of photoautotrophic, autotrophic, and heterotrophic removal of ammonia–nitrogen in aquaculture systems. Aquaculture 257, 346–358. https://doi.org/10.1016/j.aquaculture.2006.03.019)
to help develop my point of view. The publication can be consulted http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:ammonium_reductie

Yes this is good read if you want to know about the science behind carbon dosing but a somewhat more readable version was presented at the 6th International Conference on Recirculating Aquaculture. It is published here.

https://ejournals.lib.vt.edu/ijra/article/view/1336/1814

Figure 2 is important to put the ideas in this post in perspective. The bar chart reflects Jonathan’s perspective. Unless the C:N ratio is very high, you always have some autotrophic activity. Ending carbon dosing suddenly when the system is heavily dependent on heterotrophic activity to remove nitrogen seems likely to produce an ammonia spike, but you haven’t provided evidence or calculated a C:N ratio for a typical aquarium to show whether the typical aquarium heterotrophic:autotrophic ratio is on the edge of disaster. The notion to use care tapering off carbon dosing is sound advice. Whether a sudden cessation is dangerous has yet to be demonstrated.

Where I think we missed an important point in this discussion is that the ratio of heterotrophic:autotrophic may be predictive of a system’s propensity to grow nuisance photoautotrophs such as diatoms, dinoflagellates, cyanobacteria and algae. The notion that nitrate and phosphate are predictive or are the cause of nuisance organism growth needs to be revisited. It might be more useful to think in terms of inadequate heterotrophic activity or a low C:N ratio as the cause of nuisance organism growth.

Belgian Anthias
01/07/2018, 03:42 PM
Many zero emission marine aquaculture systems ( ZMAS) are managed with carbohydrate dosing and adjusted feeding. No markable nitrification and denitrification takes place in these systems. No filters are used exempt for the removal of detritus.
These systems are completely dependable of the carbohydrate doses and corresponding matched feeding rate.
How it is possible that no nitrification takes place in a system with a high carrying capacity and a very high ammonia production?
As there is no nitrate produced in the system in combination with a very high daily ammonia production, how the correct carbohydrate doses are calculated?
What will happen when dosing is not matched with the ammonia production ?

Of coarse one can not compare such ZMAS with a reef aquarium ( also a ZMAS) but the bio-chemical basics and principles are for both systems the same.

Belgian Anthias
01/07/2018, 05:01 PM
Yes this is good read if you want to know about the science behind carbon dosing but a somewhat more readable version was presented at the 6th International Conference on Recirculating Aquaculture. It is published here.

https://ejournals.lib.vt.edu/ijra/article/view/1336/1814

Figure 2 is important to put the ideas in this post in perspective. The bar chart reflects Jonathan’s perspective. Unless the C:N ratio is very high, you always have some autotrophic activity. Ending carbon dosing suddenly when the system is heavily dependent on heterotrophic activity to remove nitrogen seems likely to produce an ammonia spike, but you haven’t provided evidence or calculated a C:N ratio for a typical aquarium to show whether the typical aquarium heterotrophic:autotrophic ratio is on the edge of disaster. The notion to use care tapering off carbon dosing is sound advice. Whether a sudden cessation is dangerous has yet to be demonstrated.

Where I think we missed an important point in this discussion is that the ratio of heterotrophic:autotrophic may be predictive of a system’s propensity to grow nuisance photoautotrophs such as diatoms, dinoflagellates, cyanobacteria and algae. The notion that nitrate and phosphate are predictive or are the cause of nuisance organism growth needs to be revisited. It might be more useful to think in terms of inadequate heterotrophic activity or a low C:N ratio as the cause of nuisance organism growth.

Both publications are available and included in my article including a lot of other publications http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:ammonium_reductie

It is known that autotrophs do not care at all about the presence of heterotophs and that it is just a question of available organic carbon and competition for the same building materials. And there will be always autotrophs present in an aquarium, they will not be wiped out.
The problem is the difference in growth rate. They may be suppressed and drastic be reduced in a few hours to days, but they need time to reinstall when given the space. Autotrophic decay feeds heterotrops due increased availability of organics.

This threat is not about the influence of nitrate on the system but about how to have control over the nitrate production and removal in function of maintaining the carrying capacity needed. Most organism prefer ammonia above nitrite and nitrate as nitrogen source for celsynthesis. , Respiration is also a factor of big influence.
How to control nitrate and what is the safest way to do so.?
The fact that carbohydrate dosing will reduce the nitrification capacity is not a problem as long the carrying capacity is not changed. The problem is that when the dosing is interrupted the carrying capacity will change. When the change is to big it will have its effect and its consequences. Dangerous? A system that may loses a part of its carrying capacity from one day to an other, yes I find this situation dangerous. It is a risk one does not have to take, not for fine tuning the nitrate level.
When one messes with nature it has always consequences. It is important to know what may happen before starting messing with it.

Dan_P
01/07/2018, 07:29 PM
, The problem is that when the dosing is interrupted the carrying capacity will change. When the change is to big it will have its effect and its consequences. Dangerous? A system that may loses a part of its carrying capacity from one day to an other, yes I find this situation dangerous. It is a risk one does not have to take, not for fine tuning the nitrate level.
When one messes with nature it has always consequences. It is important to know what may happen before starting messing with it.

The C:N ratio in the reference I quoted for complete heterotrophic N assimilation is 13:1. That means a 39:1 ratio of acetic acid to ammonia nitrgen. That corresponds to a volume of vinegar of 780 mL per gram of ammonia nitrogen. I am pretty sure no aquarist is at this level of dosing, and therefore, has not pushed their system into all heterotrophic activity. A large ammonia spike does not seem like a realistic danger. Beyond this point, estimating the size of the consequence of abruptly stopping carbon additions seems impossible. To this point in time carbon dosing does not seem to have increased aquarium issues, something to be expected if many of the systems were teetering on the edge of disaster.

I understand your concern about the risk of dosing and agree with the idea to understand before attempting to adjust aquarium conditions. We disagree on the severity of the risk of carbon dosing. I think the size of the risk is testable, maybe without endangering organisms other than bacteria.

bertoni
01/07/2018, 08:06 PM
Did you find any evidence that it is not dangerous?
Yes. Years of experience with many, many tanks tell us that this approach is safe. That's as good as it gets with aquariums. In your opinion, it's dangerous or possibly dangerous. That's fine, but other people have different opinions, and what evidence we have says that carbon dosing can be done safely. Admittedly, the evidence is limited watching what happens to people's tanks rather than controlled experiments, but in the end, that's what we care about: how well the tanks perform. Aquarium science isn't going to get much funding for much beyond that.

Your references are interesting, but they do not tell us anything about the risks in our systems.

Belgian Anthias
01/08/2018, 08:23 AM
Your references are interesting, but they do not tell us anything about the risks in our systems.

You obviously did not take up much from this threat.

I try again

It is a proven fact that a situation is created which will shift the carrying capacity of the system from autotropic ammonia reduction to heterotrophic ammonia reduction. This is proven by hundreds or thousands of different labtests and practical experience using biofilters,aquaculture and aquaria systems all over the world. This shift may result in 0% nitrification capacity depending of the maintained C:N ratio. This is a fact! There is no reason to doubt about that.
As one has no control over the C:N ratio by dosing based on the nitrate level one has no idea how many nitrifying capacity is left over. This may create a dangerous situation when dosing is interrupted as the carrying capacity of the system relays on the carbo doses and may fall at once to 50% or even 0 % for a period of time. Aquarium science is not different from other basic science.
Some one who is aware of this shift knows he has to stop feeding when dosing is interrupted . Feeding must be cut back or stopped when carbo doses are cut back by half from one day to an other to avoid possible problems with the carrying capacity.

Instead of having doubts about this one should put the energy in finding a better way for dosing which prevents a high C:N ratio

There are ways to remove nitrate without bringin in danger the carrying capacity of the system.

Belgian Anthias
01/08/2018, 11:08 AM
The C:N ratio in the reference I quoted for complete heterotrophic N assimilation is 13:1. That means a 39:1 ratio of acetic acid to ammonia nitrgen. That corresponds to a volume of vinegar of 780 mL per gram of ammonia nitrogen. I am pretty sure no aquarist is at this level of dosing, and therefore, has not pushed their system into all heterotrophic activity. A large ammonia spike does not seem like a realistic danger. Beyond this point, estimating the size of the consequence of abruptly stopping carbon additions seems impossible. To this point in time carbon dosing does not seem to have increased aquarium issues, something to be expected if many of the systems were teetering on the edge of disaster.

I understand your concern about the risk of dosing and agree with the idea to understand before attempting to adjust aquarium conditions. We disagree on the severity of the risk of carbon dosing. I think the size of the risk is testable, maybe without endangering organisms other than bacteria.

An aquarium is one big biofilter.
It is a realistic danger without any doubt.

The effect of dosing carbohydrates on nitrifying biofilter are wel known. The influence of the C / N ratio on the functioning of bioreactors was extensively tested. When an efficiency of more than 95% is obtained at a C / N between 0 and 2, the efficiency falls to + - 50% at a C / N ratio of 4 and falls back to 0 at much higher ratio's. http://www.baharini.eu/baharini/doku.php?id=en:makazi:bio-chemie:biofilm#a_biofilm_for_nitrification

Everybody who drives a car does it without thinking about the consequences but the risks are known and accepted. Driving a car is one of the most dangerous things one can do. When one is aware of the risk there should be no problem. After an accident one will start the discussion what went wrong and who or what was in error. Sometimes the driver and passengers will not take part to this discussion.

Minimizing the problem is not the right approach. What is there to defend?

Precautions can be taken to limit the risk by correct dosing. Correct dosing is not possible when one only takes into account the nitrate level.
As it is difficult to measure the C:N ratio as it changes in time after each dosing and as a C:N meter does not exists.
One may start with determining the daily production of ammonia nitrogen and nitrate nitrogen production. One can have some idea and make some calculations when one knows the composition of the feed and % protein added each day. http://www.baharini.eu/baharini/doku.php?id=en:makazi:het_water:filtratie:voedselconversie A lot of work just for fine trimming nitrate.

In aquaculture systems based on carbohydrate dosing a high C:N ratio is maintained taken into account the feeding content, quantity and rate. Overdosing must be avoided, dosing must be correct to support the carrying capacity of the system as no nitrification capacity is present. In these systems no nitrate has to be removed.

There are other ways to remove nitrate which have no influence on the carrying capacity of the system at all and do not need daily attention. if they are better are more safe that is an other discussion.

Dan_P
01/08/2018, 02:43 PM
An aquarium is one big biofilter.
It is a realistic danger without any doubt

There are two components to risk: severity of the event and probability of the event. Just because a disaster is plausible, you cannot afford to worry about every plausible disaster, otherwise, you would never experiment, innovate or explore. A sound sense of proportion is needed.

For this discussion let’s call an ammonia spike troubling and one that kills fish a catastrophic failure. While catastrophic failures of aquarium biofilters are plausible, how often does that happen? Of those failures, how many were caused by rapid changes in carbon dosing? This does not prove anything except to point out that we are not experiencing an epidemic. Is this a situation that is like getting upset about the possibility of being hit by a meteor?

Where is the aquarium based data that shows a sudden, abrupt change in carbon dosing cause a serious problem? What is the chance that a “typical” aquarium is even close to the point of having a problem with a rapid decline in carbon dosing? I still agree it is plausible, but we need these answers to fully evaluate the risk.

bertoni
01/08/2018, 05:45 PM
It is a proven fact that a situation is created which will shift the carrying capacity of the system from autotropic ammonia reduction to heterotrophic ammonia reduction. This is proven by hundreds or thousands of different labtests and practical experience using biofilters,aquaculture and aquaria systems all over the world. This shift may result in 0% nitrification capacity depending of the maintained C:N ratio.
There's absolutely no reason to believe that any aquarium ever has reached the level of carbon input that would cause a problem. There is weak evidence to the contrary.

Belgian Anthias
01/08/2018, 06:53 PM
.

Where I think we missed an important point in this discussion is that the ratio of heterotrophic:autotrophic may be predictive of a system’s propensity to grow nuisance photoautotrophs such as diatoms, dinoflagellates, cyanobacteria and algae. The notion that nitrate and phosphate are predictive or are the cause of nuisance organism growth needs to be revisited. It might be more useful to think in terms of inadequate heterotrophic activity or a low C:N ratio as the cause of nuisance organism growth.

It is a fact that the nitrate level has nothing to do with the total nitrogen produced in a system. As ammonia is used directly by a lot of organism it is difficult to determine how much is used by heterotrophic and autotrophic bacteria and how much is denitrified. Nitrate is the product of autotrophs but the denitrification ratio is not known.
As most organisms prefer ammonia, also nuisance organism growth, on has to make a study of there needs. As example the C:N:P ratio for bentic algae differs a lot from the ratio needed by phytho plankton. When carbon is provided the competition will be for nitrogen and phosphate. When carbon is not provided heterotropic growth is limited by the availability of organic carbon and nitrification and denitrification will be normal which means that nitrogen may be removed from the system and not stored into the food chain and not be reused by nuisance organisms after decay. Photoautotrops will use ammonia by preference and nitrite and nitrate as emergency nitrogen source, some cyno's have one more pathway and can take up nitrogen to produce ammonia bringing nitrogen within the organic carbon chain. They will only do so to survive, when no other nitrogen source is available. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:bio-chemie:cyano Study of the pathways of the different nuisance organisms may bring more information about there typical needs.
When heterotrophic growth is responsible for limiting nuisance growth it may be due to the competition for ammonia and phosphate as the growth rate using nitrate is a lot less. I think cyno's are in favour in the competition for nitrogen as they are Phototautotropic. The limiting factor may be phosphate or other building materials. Limited availability of phosphate and building materials will have influence on all live forms.
As most organisms are in competition for the same building materials one organism my switch sooner to another pathway as an other organism according to there needs.

bertoni
01/08/2018, 06:59 PM
Photoautotrops will use ammonia by preference and nitrite and nitrate as emergency nitrogen source, some cyno's have one more pathway and can take up nitrogen to produce ammonia bringing nitrogen within the organic carbon chain. They will only do so to survive, when no other nitrogen source is available. \
I am not sure what you mean by an "emergency" nitrogen source, but many people feed nitrate to grow algae, clams, and corals. The organisms seem to do well enough. I also am not sure what you mean by "only do so to survive". Algae generally only do things in order to survive or reproduce. Ammonia probably will be taken up first. I'm not sure what relevance that has in this conversation.

Belgian Anthias
01/08/2018, 07:14 PM
There's absolutely no reason to believe that any aquarium ever has reached the level of carbon input that would cause a problem. There is weak evidence to the contrary.

There is absolutely more than one reason to believe that most aquaria where carbon is added based on the nitrate level have a carrying capacity supported for more than 50% by these doses. . Google "mixotrophic ammonia reduction" or read the listed references on the bottom of this page http://www.baharini.eu/baharini/doku.php?id=en:makazi:bio-chemie:biofilm

bertoni
01/08/2018, 07:35 PM
There are simply too many tanks that doing very well with regular carbon dosing for me to believe that they all are on the edge of a tank crash.

The part of your article (I am guessing that you wrote it?) that is in English didn't seem to have any data at all. The link isn't working at the moment, so I can't check again.

Dan_P
01/08/2018, 07:56 PM
There is absolutely more than one reason to believe that most aquaria where carbon is added based on the nitrate level have a carrying capacity supported for more than 50% by these doses. . Google "mixotrophic ammonia reduction" or read the listed references on the bottom of this page http://www.baharini.eu/baharini/doku.php?id=en:makazi:bio-chemie:biofilm

I think Jonathan’s doubt is not going to be eased by telling him to go chase references on a Google search page. Science is not a legal proceeding where showing precedence helps win the case.

At this point in the discussion, the only thing established is that you believe that there is a relatively large risk from dosing carbon, specifically, when it is abruptly stopped. You have kindly provided information that supports your hypothesis. Continuing to answer doubts about your hypothesis with references that support your beliefs will not further the discussion.

While I still think your hypothesis is plausible, we still have no data of failed aquariums or even failed aquacultures because of abrupt changes to carbon dosing. We do not yet know how likely failure to be. 100% of the time? 10%? And if there are no reports of failures, where are the stoiciometric calculations demonstrating that an abrupt change in carbon dosing for a given amount of protein input will produce an ammonia spike of so many ppm over a certain period of time for a given carbon dosing regimen?

Can you fulfill these requests for data or can you perform the calculations?

Belgian Anthias
01/08/2018, 08:02 PM
I am not sure what you mean by an "emergency" nitrogen source, but many people feed nitrate to grow algae, clams, and corals. The organisms seem to do well enough. I also am not sure what you mean by "only do so to survive". Algae generally only do things in order to survive or reproduce. Ammonia probably will be taken up first. I'm not sure what relevance that has in this conversation.

Nitrate or ammonia? The difference in energy consumption and growth rate is considerable.

if not an "emergency" let us say " last choice"

You still use the word "probably". Do you have no faith in scientific research and approved publications.? All the referenced articles in this threat are referenced with approved publications which are consult able by the interested reader.

On which approved research the advices given for carbohydrate dosing is based? Which approved references are available to dose carbohydrates by estimating the dose based on the nitrate level?

bertoni
01/08/2018, 08:16 PM
Nitrate or ammonia? The difference in energy consumption and growth rate is considerable.

if not an "emergency" let us say " last choice"
I am not sure what your point is. Whether nitrate consumption is "optimal" or not seems irrelevant to me. We are not discussing methods of maximizing growth.

You still use the word "probably". Do you have no faith in scientific research and approved publications.? All the referenced articles in this threat are referenced with approved publications which are consult able by the interested reader.

On which approved research the advices given for carbohydrate dosing is based? Which approved references are available to dose carbohydrates by estimating the dose based on the nitrate level?
As I have said repeatedly, funding for aquarium research is effectively zero, so we likely will never get high-quality data. You are postulating that a widely-used practice that has a long track record of safety. The burden of proof is on you, in my opinion.

I wouldn't call all of the articles you have referenced "scientific" nor would I call all of them "approved". In any case, none of the actual scientific papers support your assumption that aquariums getting a bit of organic carbon are in some sort of danger. Interestingly, you quote a number of articles about a successful method of aquaculture using carbon dosing, yet somehow conclude that these same article demonstrate that the technique is "dangerous". I'm still unclear how you think these tanks might fail. You have made some comments about how discontinuing the dosing might be an issue. Is there any other risk you can describe precisely?

Belgian Anthias
01/11/2018, 06:47 AM
Till now this discussion is limited to a few persons and I could not find any argument or input which demonstrates that the statement I made is incorrect and or is based on wrong interpretation of the available information . I would be happy with more funded comment.

I am not a fan of carbohydrate dosing and I made up my opinion after thorough and in depth investigation and research which can be consulted in our wiki Makazi Baharini. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:filtratie:vodka
The nitrogen cycle and how to close it in a closed marine aquarium was the base for this on going research. During years of extensive research on this theme also denitrification and the use of sulphur in biofilters was invested in depth. http://www.baharini.eu/baharini/doku.php?id=nl:badess:theorie:start
http://www.baharini.eu/baharini/doku.php?id=en:badess:start

The discussion should be about how doses can be corrected to minimise the side effects. To do this correctly, one needs correct information of the possible side effects and why advice is given to dose carbon based on the nitrate level and not on the combination of other logic parameters. As nitrate is the end product of nitrification and as it is known for a few decennia that nitrification is suppressed by adding carbohydrates this is at least remarkable.

My statement is that carbon dosing based only on the nitrate level may create an undesirable and even dangerous situation. I thoroughly explained why and why the carrying capacity of the system is effected by carbon dosing due to the shift from autotrophic ammonia reduction to heterotrophic ammonia reduction.

I do have a lot of other concerns about carbohydrate dosing of which I think users should be aware. :

The effect of explosive exponential bacterial growth and explosive exponential decay.

Impact on the nitrifying biofilm and denitrification capacity, the bio-balance on live rock and other surfaces. What is the purpose of live rock when carbohydrates are dosed?

And a lot more.

I will address my other concerns in the following contributions to this threat

For those who need more precise information, adequate information is available in our articles and consultable references published in our wiki Makazi Baharini

The past years a lot of research has been done about the biodiversity in marine aquaria and other marine aquaculture systems. AOA, ANAMMOX in aquarium biofilters, simultane nitrification and mixotropic denitrification on sulphur , new players, new developments. ( not really new because they have always been part of the game)
A recent development is the knowledge that most of autotropic amonia reduction ( nitrification) in aquaria is not done by bacteria but instead by Archaea (AOA) http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:aoa_ammonium_oxiderende_archaeabacteria

Belgian Anthias
01/11/2018, 08:00 AM
Where I think we missed an important point in this discussion is that the ratio of heterotrophic:autotrophic may be predictive of a system’s propensity to grow nuisance photoautotrophs such as diatoms, dinoflagellates, cyanobacteria and algae. The notion that nitrate and phosphate are predictive or are the cause of nuisance organism growth needs to be revisited. It might be more useful to think in terms of inadequate heterotrophic activity or a low C:N ratio as the cause of nuisance organism growth.

Does the redfield ratio or C:N ratio or N:P ratio in the water column has any effect on nuisance growth? Probably as most organisms are triggered by there environment.
But as each organism has its own way to respond on this environment they will take what they need from the total available building materials and battle only for what is left.
Can we remove bentic algae with C:N:P 550:30:1, by maintaining the N:P ratio at 16:1 in the water column. I do not think so.http://www.baharini.eu/baharini/doku.php?id=nl:makazi:chemie:redfield
One needs to look at the specific needs of the specimen.

Normally most processes concerning the nitrogen cycle are surface related and take place in a biofilm and not in the water column. The situation in the biofilm is completely different and exchange of the building materials only takes place at the surface of the film.
When ammonia and other building materials are removed fast out of the water column and a lot of oxygen is used due to a high heterotropic activity in the water column this ammonia and building materials are not available for building up and maintaining the biofilm; Is a biofilm a nuisance?
The same for bentic algae as most of the total available ammonia will be used up by heterotrops and phytoplankton in the water column. The effect of algae growth in combination with carbon dosing has been a subject of a lot of research. A high C:N ratio will influence the growth of bentic and other algae, can even prevent it. But is it better, as algae can easily be harvested? What is a nuisance?
Adding carbohydrates will suppress bentic growth which is dependable of the supply from the water column.
Doses must be made correctly in function of the result

The effect on a mixed reef aquarium, the bacterial balance between specific bacteria and corals?

Dan_P
01/11/2018, 10:37 AM
Till now this discussion is limited to a few persons and I could not find any argument or input which demonstrates that the statement I made is incorrect and or is based on wrong interpretation of the available information . I would be happy with more funded comment.

Science is more than debating or deciding on the validity of an idea based on the number of papers you can quote. I have said repeatedly the you have a plausible arguement, but there is a big difference between plausible and scientifically proven. I think Jonathan is getting to this very point when he asks for aquarium data that supports your idea. Unless all the carbon dosers have been very, very lucky so far, the notion that carbon dosing is inherently risky, dangerous and bad is probably an incomplete idea.

Since you have read so many scientific papers, you will appreciate that in this discussion we have only got through the “introduction”, where the issue is presented, the literature is summarized and the study of the hypothesis justified. To progress any further, we will need experimental data or at least a thorough modeling of the typical aquarium with and without carbo dosing. In science it is up to you, the presenter of the hypothesis to prove your point.

Good Luck!

Dan

bertoni
01/11/2018, 04:17 PM
Till now this discussion is limited to a few persons and I could not find any argument or input which demonstrates that the statement I made is incorrect and or is based on wrong interpretation of the available information .
You are welcome to your opinion. I don't find the evidence you have presented to be convincing. We will have to continue to disagree.

Belgian Anthias
01/11/2018, 05:41 PM
I am not sure what your point is. Whether nitrate consumption is "optimal" or not seems irrelevant to me. We are not discussing methods of maximizing growth.

As I have said repeatedly, funding for aquarium research is effectively zero, so we likely will never get high-quality data. You are postulating that a widely-used practice that has a long track record of safety. The burden of proof is on you, in my opinion.




I wanted to point out that the growth rate when using ammonia is not maintained when using nitrate. For commercial farming this is an important issue.

Not all research is funded.
Not all research is done for commercial purposes.
A lot of research has been done for master thesis’s.
Marine aquaculture is booming business.
A lot of research is done for and in public aquaria.
There has been a lot of funded research recently on closed marine systems and its biofilters. AOA , ANAMMOX, COMAMMOX was detected due to extend research on aquarium bio systems.


All articles which are used as references in this threat are based on research on which is referred to in the article. How and why!

Managing a commercial ZMAS based on carbon dosing is only possible due to previous research. It is not on experimental base as is carbohydrate dosing in a marine aquarium on the present day.

No home aquarium is the same but bio-chemical principles in seawater are the same in all closed marine systems.

No biofilm will be exactly the same but the principles on how the bacteria connect and communicate are for all biofilm the same.

We did a lot of research to find out how and why? if you want to fund our research and support our wiki Makazi Baharini, donations are possible! Link available on demand! Our research is accessible for free.

Belgian Anthias
01/11/2018, 06:14 PM
You are welcome to your opinion. I don't find the evidence you have presented to be convincing. We will have to continue to disagree.

Is it disagreement or deniel?

No evidence has been provided as far that the information is not correct.

bertoni
01/11/2018, 06:42 PM
Given the number of tanks that are successful with carbon dosing, with no signs of trouble, I don't think I'm in denial. I've never heard of even one tank going through the type of collapse that you are positing.

Belgian Anthias
01/12/2018, 06:06 PM
When one messes with nature assuming nothing can go wrong one may expect disaster.
It is good to know what is happening while manipulating nature to prevent something may go wrong and what to do when it expectedly or unexpectedly goes wrong. That is why we do research. To know how nature works to be able NOT to mess with it but use nature into our favour.

Before adding supplemental organic carbon to a live support system some questions needed answers.

During carbohydrate dosing:
What happens to the carrying capacity of the system?
What happens to the established biological balance ?
What happens to the nitrification and denitrification capacity installed in the system?
What changes within live rock during carbohydrate dosing? In DSB and other biofilters?

And most important:
What may happen to an aquarium system in which the nitrate level is kept in balance using carbohydrates when for some reason dosing is stopped or interrupted?

Are the imposed changes of no significance? Can the changes have consequences? Can they create a dangerous situation or even be disastrous?

Are the taken risks accountable for the results

How much carbohydrates must be used to lower the nitrate level?
A simple question when all parameters are taken into account. How to determine the parameters needed?

We where able to answer all the above questions with the exception of the last one.

We know that keeping on a high C:N ratio will shift the carrying capacity to heterotropic ammonia reduction.
When organic carbon doses are based on the nitrate level one has no control over the C:N ratio and in a situation where the shift is completed the carrying capacity of the system will become dependable of the carbohydrate supplements. For me such situation is a threat for the continuity of the system and is best avoided ?

My conclusion:

As the C:N ratio in the aquarium is not controlled by the way dosing is done for the moment, carbohydrate dosing is not without risk.

Compared with the possible influence of the nitrate level on the system, the influence on the system by recycling some of this nitrate by carbon dosing is huge and may create a most undesirable situation.
Is it worth the drastic changes induced by carbohydrate supplements to the installed biological balance and carrying capacity of the system just for reducing some nitrate?

Belgian Anthias
01/13/2018, 08:41 AM
I wondered about this. This is probably the explanation for the delay in nitrate reduction when dosing is started.



A lot of carbon goes into energy requirements, production of CO2. I think something like more than 50% of the carbon consumed goes to CO2. This is one factor preventing aquaria from turning into sewage plants.

Not only the fact that ammonia is used first is responsible for the delay. Bacteria coming into contact with a new environment go in there Lag phase ( Bacteria population growth has four phases: Lag, Log, steady, dying ) This is the phase for the bacteria to adapt to the new environment by adjusting there internal pathways, building up tools and modify processing installations, to what is coming and do necessary repairs. The population thus not grow. This phase may take some time, Form one hour to several days. Than the cell will grow to double it's size and the Log phase is started http://www.baharini.eu/baharini/doku.php?id=nl:makazi:bio-chemie:bacteri%C3%ABn#de_groei
As nothing happens to the nitrate level during this Lag phase and during ammonia take up in the Log Phase, users who are not patient enough my add more carbohydrates creating a bacterial bloom in the Log phase. As the growth is exponential also the dying phase will be exponential as the cells of the same generation will start the dying phase at the same time. When the growth is explosive also the dying phase will be explosive which causes a lot of stress within a closed live support system. Bacterial bloom is not that innocent as one often can read due to explosive consumption of oxygen and building materials and following explosive decay of biomass.

A lot of commercial organic carbon additives contain bacteria cultures. Even when these cultures would come to live I am pretty shore that the Lag phase may take a lot of time, more time as the installed bacteria may need.

If all organic matter would be oxidized during re-mineralisation, all organic carbon would be transformed into CO2 http://www.baharini.eu/baharini/doku.php?id=nl:badess:theorie:stikstofkringloop#remineralisatie That is why nature let heterotropic bacteria grow +-5X faster as autotrophic bacteria. if it was the opposite no organic carbon would be available.
As a closed aquarium system is not really closed as it is still in contact with the atmosphere the side effects of messing with the carbon balance will not provoce much problems. In a system where bioreactors are used this is a complete other story.

A lot of people add products to aquaria of which they do not know what the side effects may or will be?

nogascans
01/16/2018, 01:58 PM
Very interesting and openly debated thread which I find refreshing. I don't have much scientific input to add (took a high paying job and never used my marine science schooling).

An observation of my experience and to see if anything may relate. In advance I am sorry if there is nothing here to add to discussion.

I recently (Late December) put together a new tank (Red Sea Reefer 750XXL), and moved over a week all my livestock, rock (new sand) from existing 90 bow-front to new tank.

Older tank was sump-less, and utilized a Bio-Pellet reactor with HOB skimmer which has been in use for last 4+ years. Tank was a mixed/heavy SPS tank, and fish health was always good, coral growth/coloration average with growth and good/not great colors. Generic 6-Bulb T5HO for lighting. Older tank was never an algae magnet, and never saw any HA, Bryopsis, or Dinoflagellates during tank life.

New tank has a sump and I transferred Chaetomorpha/Pods from established system to new tank. Did not run a normal cycle, but instead relied on existing Bio-mass in substrate (130 lb. of existing encrusted rock). Using a new R/O Classic 202S, 3100 GPH return pump, and pair of MP40QD for filtration and flow. I used all new water (Fritz) at same parameters as old tank for Alk, Ca, and Mg (8.5, 430, 1380). ATI 8 bulb T5HO for lighting in tank and LED light for Sump.

I have monitored for ammonia and never saw any measurable signs. I had no noticeable negative effects to corals, and continued encrusting was noticed from day 1. I used PAR meter to adjust lighting to previous tank lighting to try and eliminate any coral shock. I did note immediate improvement in coloration on all SPS, along with some initial lightening of LPS present. Chaeto has grown at a steady state. I have been fighting very low Nitrates <1 (Red Sea) and phosphates <.17ppb (Hanna ULR).

I did experience the "normal" diatom bloom with new rock (was washed before use. I have been fighting a small Dino outbreak at week 3, and not sure if part of a mini-cycle or some of the imbalance issues discussed here with reduction or loss of colonized nitrifying bacteria cultures. Not a terrible by any means outbreak, and use of filter bags has eliminated most of signs without lighting reductions.

Other than a swift and complete stop to organic dosing, I just thought my case was worth mentioning and that it might show some light on the subject being discussed.

Sincerely,

David

bertoni
01/16/2018, 03:40 PM
Data always are interesting. :)

Did you disconnect the bio-pellet reactor for the move? I was a bit unsure on that point.

Belgian Anthias
01/17/2018, 01:58 AM
What kind of bio-pellets where used?
Do they leak( dose) organic carbon into the water column or is the carbon available only for the bacteria growing on it?

nogascans
01/17/2018, 11:23 AM
Data always are interesting. :)

Did you disconnect the bio-pellet reactor for the move? I was a bit unsure on that point.

I left it running in old tank until I moved rock (bucket flushed with new water and into new tank). I did not transfer BP to new tank.

Sincerely,

David

nogascans
01/17/2018, 11:29 AM
What kind of bio-pellets where used?
Do they leak( dose) organic carbon into the water column or is the carbon available only for the bacteria growing on it?

I used the BRS brand, and have been for several years. I liked the way they broke down and that made it easier to get correct flow. Active bacteria was visible on media as well as large population of tube worms, etc.:

https://www.bulkreefsupply.com/brs-bulk-biopellets.html

Sincerely,

David

bertoni
01/17/2018, 01:03 PM
Thank you for the clarification!

Belgian Anthias
01/18/2018, 03:53 AM
Biopellets are made of PHA but there are a lot of different monomers possible containing different quantities of carbon and hydrogen . No specs available for BRS bulk pellets about carbon content but they claim to be 100% pure PHA. Biologically cultivated PHA may be +- 70% of the total dry mass. To get pure PHA in most cases solvents are used. To let it stick together to make pellets some additives must be added.
It is also claimed that:

Nitrate laden Bacteria is removed via the protein skimmer
Bacteria directly converts nitrite into nitrous oxide, so nitrate is never produced
Bacteria consumes nitrates and processes them down into nitrogen gas
Nitrate laden Bacteria is consumed by tank inhabitants like corals and sponges

All needs some explanation!



It is not that difficult to cultivate PHA


Used in a " tumbling reactor" , a moving bed reactor, erosion is high and particles of the pellets will spread into the water column. The PHA becomes part of TOC. The dose organic carbon released and available in the water column is difficult to determine, is not controlled, This way a high C:N ratio is possible in the water column.

When the erosion is limited by preventing tumbling the reactor may clog due to the growth.. The supply to the reactor can be managed by the flow rate which gives some control.
As in the reactor enough carbon is available the limiting factor will be the available other building materials as nitrogen and phosphate. As building materials present in the reactor may be used up, most bacteria and archaea may start to make there own PHA which will be used when they spread in the aquarium.

An unexpected bacterial bloom! Can it be caused by bacteria who have started to use there stored PHA.?

Belgian Anthias
01/23/2018, 11:54 AM
Before starting adding supplements to an aquarium on should have some basic knowledge about how bacteria grow and what are the main differences between heterotrophs and autotrophs. A lot of commercial organic carbon additives claim to contain dried bacteria and building materials. Why dried bacteria?
Starters often use supplements of dried nitrifiers in the hope to speed up the nitrifying capacity to support the carrying capacity. Why the need to speed it up?
One must be aware that all these efforts may be for nothing when in a later phase organic carbon will be dosed to control nitrate.
Why not start up the system dosing organic carbon preparations containing bacteria, minerals and all building materials, ?
I found some interesting basic information on the internet which can be used to start the discussion. http://neospark.com/images/AutotropVsHeterotrop.pdf

Tripod1404
01/23/2018, 03:53 PM
As a side note, you can (atleast in certain tanks) achieve carbon dosing-like effects by dosing amino acids.

For example, I dose amino acids to reduce nitrate levels and decrease dosing if I want it to increase nitrate. It actually sometimes cause my system to go very nitrate limited and I have to add a mixture of potassium and sodium nitrate to increase nitrate. During this period I have to stop dosing amino acids otherwise nitrate is quickly consumed. I read people who dose amino acids sometimes made similar observations.

Considering bulkier amino acids with large side chains actually have more carbon than nitrogen, it is not that surprising. For example tyrosine has 9 carbons and 1 nitrogen, tryptophan has 11 carbons and 2 nitrogen, as a comparison acetic acid and methanol has 1 carbon and ethanol has 2 carbons.

The only main difference for dosing amino acids is the technical difficulty as you would need to turn of the skimmer for 30 mins to 1 hour, otherwise the skimmer would remove most of what is dosed (at least hydrophobic amino acids).


Therefore I prefer the term "carbon" dosing rather than "carbohydrate" dosing. Amino acids are not carbohydrates but you can achieve the same outcome. From a pure organic chemistry perspective, neither are ethanol or methanol are carbohydrates (FDA sometimes classified ethanol as a carbohydrate but it is scientifically inaccurate), they are alcohols and they dont have the correct hydrogen/oxygen ratio to be classified as carbohydrates. Only alcohols that can be considered as carbohydrates are sugar-alcohols (polyols) like glycerol, sorbitol, manitol, etc. Most carbohydrates are polyhydroxyl derivatives of ketones and aldehydes and that even makes acetic/ethanoic acid a questionable carbohydrate since it is hard to argue it is polyhydroxylated (more like monohydroxylated).

bertoni
01/23/2018, 05:59 PM
I'm not sure why amino acids would work better for nitrate reduction, since they are a nitrogen source. I agree that the amount of carbon per unit of nitrate is significant, though. Maybe some organism is limited in growth by a missing amino acid. I'd stick with vinegar, ethanol, or bio-pellets for nitrate reduction, at least for a first attempt, but amino acid dosing can be helpful, at least in theory, depending on what's in the food going into the tank. It's interesting that you get good results. Maybe we should encourage others to give it a shot if they're stuck. More puzzles.

Dan_P
01/23/2018, 08:13 PM
The only main difference for dosing amino acids is the technical difficulty as you would need to turn of the skimmer for 30 mins to 1 hour, otherwise the skimmer would remove most of what is dosed (at least hydrophobic amino acids).

Usually hours are required for the entire tank volume to be treated by the skimmer and that says nothing about the recovery rate, just passing through the skimmer. Recovery, or in this case loss of the amino acid, by skimming will likely be slow, more so if the skimmer is making dry foam. Keep the skimmer on, the bacteria will harvest the amino acid faster than any skimmer could.

Tripod1404
01/23/2018, 09:16 PM
I'm not sure why amino acids would work better for nitrate reduction, since they are a nitrogen source. I agree that the amount of carbon per unit of nitrate is significant, though. Maybe some organism is limited in growth by a missing amino acid. I'd stick with vinegar, ethanol, or bio-pellets for nitrate reduction, at least for a first attempt, but amino acid dosing can be helpful, at least in theory, depending on what's in the food going into the tank. It's interesting that you get good results. Maybe we should encourage others to give it a shot if they're stuck. More puzzles.

Yeah that is the question. I actually accidentally realized this. I was trying to raise nitrates by dosing amino acids, but more I dosed more it reduced ( I actually dropped to undetectable NO3 levels on salifert kit). Than I decided something was not right, I stopped dosing aminos and nitrate slowly started to increase. After that I started to use a mixture KNO3 and NaNO3 to increase nitrate. After that I realized dosing aminos increase nitrate consumption. Actually to a point that if you dose them together, nearly half of dosed nitrate disappears the next day.

While thinking about it I realized that at cellular level, it is quite common for cells to convert glucogenic amino acids to glucose and ketogenic amino acids to fatty acids. Actually this is how the metabolisms of carnivores work, their diets are very poor in carbohydrates (and fats depending on source) they basically convert amino acids to sugars and fats.

Now we dont know the exact amino acids composition of the amino acid additives. But if they have a large content of large amino acids like tyrosine, tryptophan, etc , it would mean they contain a lot more carbon than nitrogen. Plus these large amino acids are not very abundant in proteins, generally smaller amino acids are a lot more common. Below is a link showing the average amino acid content of E.coli proteins;

http://kirschner.med.harvard.edu/files/bionumbers/Amino%20acid%20composition%20of%20the%20proteins%20from%20E.%20coli%20cell%20supernatant.pdf

4 most common amino acids found in E.coli proteins is glutamate(5C,1N), asparatate(4C,1N), alanine (3C,1N) and glycine (2C,1N) . Aside from this I know glycine is commonly produced by cells as a osmoregulator, so it might be a lot more common outside of proteins. And 4 least common amino acids are tryptophan (11C, 2N) histidine (6C 3N), methionine (5C, 1N) and tyrosine (9C, 1N).

So if the amino acid supplement contained a lot of large amino acids, it would force cells break down the large amino acids and to absorb more nitrogen from the environment, in order to produce more of the smaller, more common amino acids. Like from a 11C tryptophan has enough carbon to built 5.5 glycine. But it only contain 2N, so to built 5.5 glycines a cell would need to pick up 3.5 molecules of nitrate. So it would cause nitrate uptake.

Does it provide any benefit over regular vinegar dosing, I doubt this. The only possible benefit might be uptake of some of the amino acids by corals and other inverts (especially clams). Plus it is hard to overdose it and excess can be removed by the skimmer. But it is far more expensive and can get contaminated.

Tripod1404
01/23/2018, 09:18 PM
Usually hours are required for the entire tank volume to be treated by the skimmer and that says nothing about the recovery rate, just passing through the skimmer. Recovery, or in this case loss of the amino acid, by skimming will likely be slow, more so if the skimmer is making dry foam. Keep the skimmer on, the bacteria will harvest the amino acid faster than any skimmer could.

I use a over sized skimmer, so I am very cautious about how much skimming is going on. Aside from that it causes the skimmer to foam like crazy and overflow, if I dont turn it off.

Belgian Anthias
01/24/2018, 09:31 AM
How difficult and expensive one can make a simple task as removing non toxic nitrate?

Do we want to remove the nitrogen or assimilate and recycle it?
Depending of the daily quantity nitrate to remove.
Do we want to keep the present nitrification capacity or shift the ammonium reduction towards organic carbon availability and bacterial growth?
Labor-intensive or normal maintenance practice?
Are all side effects known and how they are prevented?

Removing nitrate? Just controlling the nitrate level? Or do we want to have full control over the daily nitrate removal rate and close the nitrogen cycle?

For removing nitrate from the system we have to reduce it to nitrogen gas.
Controlling the nitrate level is possible both ways, denitrification or assimilation, depending of how much nitrate has to be reduced on a daily base. ( preventing bacterial slime, high C:N ratio's)
For full control over the daily nitrate removal rate one needs a bioreactor and have control over the HRT, the flow rate.
Simultane nitrification and mixotropic denitrification in one bioreactor is a possibility.

How one can obtain full control over the daily nitrate uptake rate using carbohydrates?

The most simple and easily applied method for removing nitrate and on which I have done some research, suitable for having control over the nitrate level , is the SPC method, sulphur packed columns. A mix of oystershell gravel and elemental sulphur beats putted in a filter bag and hung freely in the water column. Very cheap, very effective and very low maintenance. http://www.baharini.eu/baharini/doku.php?id=nl:badess:bades_bio_filter#het_zwavelkolommen_systeem

Dan_P
01/24/2018, 09:43 AM
Yeah that is the question. I actually accidentally realized this. I was trying to raise nitrates by dosing amino acids, but more I dosed more it reduced ( I actually dropped to undetectable NO3 levels on salifert kit). Than I decided something was not right, I stopped dosing aminos and nitrate slowly started to increase.

Interesting observation!

Dan_P
01/24/2018, 09:45 AM
I use a over sized skimmer, so I am very cautious about how much skimming is going on. Aside from that it causes the skimmer to foam like crazy and overflow, if I dont turn it off.

How many ppm of amino acids are you adding? Which ones seem to cause the most foam?

Tripod1404
01/24/2018, 11:14 AM
How many ppm of amino acids are you adding? Which ones seem to cause the most foam?

I dont prepare my amino acid stock solutions. I use commercial amino acid supplements like; acropower, KZ LPS aminos acids and red sea reef energy B.

I generally dose 10-15ml of one of these products to ~120G tank daily. If that days nitrate tests gave less than ~0.5ppm nitrate, I dose half the amount. Among these acropower cause the most foaming. Even after 1 hour of turning the skimmer off, it still foams if what is dosed is acropower. I think this is because acropower is the most concentrated product among these. Manufacturer Recommended dosing amount of AP is ~1/10 of the other brands(but it still dose 10-15ml).

Tripod1404
01/24/2018, 12:09 PM
How difficult and expensive one can make a simple task as removing non toxic nitrate?

Do we want to remove the nitrogen or assimilate and recycle it?
Depending of the daily quantity nitrate to remove.
Do we want to keep the present nitrification capacity or shift the ammonium reduction towards organic carbon availability and bacterial growth?
Labor-intensive or normal maintenance practice?
Are all side effects known and how they are prevented?

Removing nitrate? Just controlling the nitrate level? Or do we want to have full control over the daily nitrate removal rate and close the nitrogen cycle?

For removing nitrate from the system we have to reduce it to nitrogen gas.
Controlling the nitrate level is possible both ways, denitrification or assimilation, depending of how much nitrate has to be reduced on a daily base. ( preventing bacterial slime, high C:N ratio's)
For full control over the daily nitrate removal rate one needs a bioreactor and have control over the HRT, the flow rate.
Simultane nitrification and mixotropic denitrification in one bioreactor is a possibility.

How one can obtain full control over the daily nitrate uptake rate using carbohydrates?

The most simple and easily applied method for removing nitrate and on which I have done some research, suitable for having control over the nitrate level , is the SPC method, sulphur packed columns. A mix of oystershell gravel and elemental sulphur beats putted in a filter bag and hung freely in the water column. Very cheap, very effective and very low maintenance. http://www.baharini.eu/baharini/doku.php?id=nl:badess:bades_bio_filter#het_zwavelkolommen_systeem

Well ,removing nitrate from the system does not require it to be reduced to nitrogen gas. Whole bacteria can be skimmed out of the tank, together with nitrogen containing bio-molecules, about 3-5% of a cell is nitrogen anyways. I am skeptical about carbon dosing increasing nitrate reduction into nitrogen gas. That process is severely inhibited by oxygen. So if we assume it only happens at regions that oxygen cannot diffuse, we should also assume larger organic carbon sources wont diffuse to these bacteria as well. I have read interesting theories about carbon dosing increasing the oxygen consumption by bacteria, forcing them (especially the ones living deeper within the bacterial mat) to become facultatively anaerobic for some period. But I doubt this state would last long enough to have signification reduction into N2 gas.

In my opinion carbon dosing causes bacteria population to increase. Building more bacteria requires more nitrogen, so ammonia/nitrite/nitrate is taken up by growing bacteria. Some of these bacteria gets waterborne and skimmed out by the skimmer, effectively exporting nitrogen out of the system.

I get what you mean by saying this process makes nitrogen export dependent organic carbon availability. But the alternative you described is not that different. The only difference is you make the process dependent on elemental sulfur availability. By giving them sulfur to reduce, you allow them to chemotrophicly fix carbon dioxide. So in some ways that is indirect carbon dosing . Similar to growing algae and allowing them to fix carbon phototrophicly and absorb nitrogen for growth.

In the end an aquarium is a closed system. As much as we want it to be, it is not an ecosystem, it is not self sufficient. In a ecosystem biomass is composed of autotrophs (mainly plants and algae) >> simple heterotrophs (bacteria, fungi and other microorganisms) >> complex heterotrophs (animals). In an aquarium, the biomass is almost flipped, we have complex heterotrophs > simple heterotrophs >> autotrophs. Such a system cant be functioning without external input.

bertoni
01/24/2018, 05:26 PM
I think you meant, "an aquarium is not a closed system"?

I agree that nitrogen gas is just one path out of the system for nitrogen. Skimming bacteria or bacterial output both could be important. I have read differing opinions on which is more likely in the skimmate.

Tripod1404
01/24/2018, 05:36 PM
I think you meant, "an aquarium is not a closed system"?

I agree that nitrogen gas is just one path out of the system for nitrogen. Skimming bacteria or bacterial output both could be important. I have read differing opinions on which is more likely in the skimmate.

Yeah not a closed system :)

Dan_P
01/24/2018, 07:34 PM
Skimming bacteria or bacterial output both could be important. I have read differing opinions on which is more likely in the skimmate.

Just to clarify, there is a debate (little or no data) on which material, bacteria or extracellular bacterial matter, is more important in exporting nitrogen compounds?

bertoni
01/24/2018, 08:14 PM
As far as I know, there's little or no data on what's actually happening with carbon dosing. It might vary from system to system, for that matter.

Dan_P
01/25/2018, 07:15 AM
As far as I know, there's little or no data on what's actually happening with carbon dosing. It might vary from system to system, for that matter.

Thanks. Just wanted to clarify before I start looking for difference post dosing. Since I just started, I don’t expect to see anything, although at 4 mL per 50 gallons (18 daily doses at this point) skimmer output seems to have increased. I say seems because data is noisy and more is needed to confirm a trend.

Belgian Anthias
01/25/2018, 09:11 AM
Well ,removing nitrate from the system does not require it to be reduced to nitrogen gas. Whole bacteria can be skimmed out of the tank, together with nitrogen containing bio-molecules, about 3-5% of a cell is nitrogen anyways.

Research has confirmed the removal of live bacteria. To some extend. Most of the removed bacteria are not skimmed of but carried out on the surface of the foam. The removal is limited and very selective. Some trains are removed, some stains are not. This may have consequences for the evolution of bacterial populations and bacterial balances within the aquarium and is considered an important item on the negative side of the use of skimmers. http://www.baharini.eu/baharini/doku.php?id=en:makazi:het_water:filtratie:eiwitafschuimer

I am skeptical about carbon dosing increasing nitrate reduction into nitrogen gas. That process is severely inhibited by oxygen. So if we assume it only happens at regions that oxygen cannot diffuse, we should also assume larger organic carbon sources wont diffuse to these bacteria as well. I have read interesting theories about carbon dosing increasing the oxygen consumption by bacteria, forcing them (especially the ones living deeper within the bacterial mat) to become facultatively anaerobic for some period. But I doubt this state would last long enough to have signification reduction into N2 gas.

A lot of heterothropic strains are able to simultane nitrification and aerobe denitrification incl Acinetobacter sp. Normally the contribution to the nitrogen cycle is very limited as autotrophic nitrification is a lot more effective and efficient for this purpose. They prefer ammonium as nitrogen source. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:bio-chemie:shnad&s[]=acinetobacter&s[]=sp
IIn all balanced aerobic nitrifying biofilms denitrification takes place.


In my opinion carbon dosing causes bacteria population to increase. Building more bacteria requires more nitrogen, so ammonia/nitrite/nitrate is taken up by growing bacteria. Some of these bacteria gets waterborne and skimmed out by the skimmer, effectively exporting nitrogen out of the system.

The export of live bacteria is very limited and max 35% of total organics ( TOC) is removed by a skimmer. The export is very limited and the rest is recycled , when consumed it becomes part of the food chain. Carbon dosing does effectively removes some nitrogen with all other building materials which must be supplemented. The export rate is unknown and can not be predicted.

I get what you mean by saying this process makes nitrogen export dependent organic carbon availability. Bit becomes part of the food chainut the alternative you described is not that different. The only difference is you make the process dependent on elemental sulfur availability. By giving them sulfur to reduce, you allow them to chemotrophicly fix carbon dioxide. So in some ways that is indirect carbon dosing . Similar to growing algae and allowing them to fix carbon phototrophicly and absorb nitrogen for growth.

I have stated that ammonium reduction becomes carbon dose dependable, not the export of nitrogen which relies on the skimmer. The ammonium removal capacity determines the carrying capacity of the system. The nitrogen export of carbon dosing is very limited and the removal rate is unknown as most nitrogen is recycled within the system.

The carrying capacity of the system is not supported by using sulphur as a base for a biofilm as ammonia is reduced by nitrification. Providing sulphur increases the denitrification capacity and denitrification of nitrate to nitrogen gas thus not influence the carrying capacity at all.
I do not understand the link between sulphur and carbon dosing. We do not need sulphur to provide CO2. The process uses carbonate as carbon source which is provided by the calcium carbonate. The sulphur is used as energy source, No dosing. Low maintenance.
We do need carbon dosing to provide organic carbon, A task of great importance once the system is shifted from autotrophic to heterotropic ammonia reduction.

In the end an aquarium is a closed system. As much as we want it to be, it is not an ecosystem, it is not self sufficient. In a ecosystem biomass is composed of autotrophs (mainly plants and algae) >> simple heterotrophs (bacteria, fungi and other microorganisms) >> complex heterotrophs (animals). In an aquarium, the biomass is almost flipped, we have complex heterotrophs > simple heterotrophs >> autotrophs. Such a system cant be functioning without external input.

One can obtain full control over the nitrogen cycle and close the nitrogen cycle in an aquarium system. But not with carbon dosing, I can not see how as the nitrogen export can not be determined.
Nitrogen not exported can suddenly accumulate, hopefully as nitrate and not as ammonia

In ZMAS aquaculture systems based on carbon dosing the food-cycle is closed as long there is enough growth. All nitrogen is exported when the bio-load is harvested.

Belgian Anthias
01/25/2018, 10:51 AM
Just to clarify, there is a debate (little or no data) on which material, bacteria or extracellular bacterial matter, is more important in exporting nitrogen compounds?


Because of the importance of certain strains of bacteria for the health of corals, research is started to know if these strains are removed or not by a skimmer. As these strains are in less quantities present in the aquarium as in nature one may assume they are skimmed but this is not confirmed to my knowledge.
Any way, it is confirmed by thorough research that the total removal of live bacteria out of the water column is limited ad selective. And as a lot bacteria fed by carbon dosing are bentic !?

Why adding something to a live support system when one does not know what happens when one does so? The reason must be very important, to correct a more dangerous situation.
To remove something as nitrate, not a threat for a system at all?

How much data you need concerning carbon dosing? Carbon dosing is very extensively researched for commercial aquaculture purposes. A lot of this date I have in our data base.
You may start here: http://www.baharini.eu/baharini/doku.php?id=en:makazi:het_water:filtratie:eiwitafschuimer Use the references

The main processes are the same as for aquaculture systems, the side effects may be completely different. The shift from autotrohpic to heterotrophic ammonia reduction to be the most important.

A simple question as: How much vodka has to be dosed daily to lower the nitrate level with 1ppm daily? may become complex if one does not know how much nitrate is produced daily and how much nitrogen and carbon is added by feeding.

Advices for dosing are given based on the presence of nitrate , without knowing the daily nitrate over-production and feed content in protein, In mg/100 lit based on assumptions, trail and error!? One has no clue of the C/N ratio after dosing and before dosing the next dose.

Why not make doses based on known factors ?

When it comes to nitrogen export from the system in comparison with nitrification/denitrification, there should be no debate as carbon dosing does not export nitrogen; The nitrogen export is done by a third party and depends entirely on ability of the skimmer. The ability of a skimmer to remove live bacteria and organics is known and needs no debate any more.

DiscusHeckel
01/25/2018, 11:23 AM
Have your research papers appeared in a peer reviewed journal? If so, would you mind providing their citation please?

Thank you.

Tripod1404
01/25/2018, 12:52 PM
One can obtain full control over the nitrogen cycle and close the nitrogen cycle in an aquarium system. But not with carbon dosing, I can not see how as the nitrogen export can not be determined.
Nitrogen not exported can suddenly accumulate, hopefully as nitrate and not as ammonia

In ZMAS aquaculture systems based on carbon dosing the food-cycle is closed as long there is enough growth. All nitrogen is exported when the bio-load is harvested.

I dont get what is the difference between being "skimmed out" and "being carried on the surface of the foam". What is skimmed out is also being carried on the surface of the foam, that his how a foam fractionator function. I dont think it matters that much as long as it ends up in the collection cup.

Also for the 35% of total removed organic matter being bacteria, is that the value with carbon dosing or is the the amount removed in a tank w/o carbon dosing ? Because carbon dosing is known to significantly increase skimmer output. The increase is most likely bacteria or bacteria-based molecules.

Even than 35% is not a small number. I would actually expect the value to be a lot less. That is like 1.5% of removed organics is nitrogen inside bacteria. And like Bertoni pointed you dont have to remove intact bacteria, bacteria based products can also achieve this. Some bacteria that gets into foam will lyse before they can reach the collection cup, some will die or lyse within the tank and their contents will end up in skimmer. So you wont just have bacteria within the skimate, but the bacterial content. So the actual indirect export can be a lot higher. There would also be output from stuff like bacteria that is being consumed by other organisms (like bacteria ->copepod->fish). In my experience carbon dosing increase copepod populations, which indicate nitrogen in these bacteria can end up in a variety of different members of an aquarium. And from there nitorgen can go to skimmer, like in fish poop form or continue to be recycled among the organisms. These indirect outputs would be something hard to measure, you can potentially dose carbon-14 ethanol or acetic acid and make a radioactive tracing to see how much of it end up in the skimmer, fish and etc. and extrapolate a rough number for nitrogen (like 1 nitrogen atom for every 6 carbon atoms, which is the average ratio within a cell ). But I dont think anybody is doing or done this.

I am not disagreeing that autotrophic nitrification is a lot more effective, but here I assume you are talking about sulfur based chemo-autotrophic assimilation. This is something I am very wary about the long term safety. I personally know someone whose tank nearly crashed to a sudden burst of H2S production. For an autotrophic assimilation nitrate process, using macro-algae or even mangroves is a lot safer.

Is regular carbon dosing completely safe,of course no. It can cause bacteria blooms and suffocate the tank. It depletes some elements that we do not regularly test for (most notably potassium). But I have never heard anybody experiencing a sudden ammonia burst during carbon dosing. Considering carbon dosing is probably being done by thousands of people, lack of empirical evidence suggest it is not as likely as you suggest it to be.

And all in all there is one major problem. What you describe can only reduce nitrate but not phosphate. So you need an additional mechanisms to control phosphate, likely GFO or aluminum based absorbents. When you add these do the mix, it generally make the system phosphate limited and would effectively reduce the efficiency of nitrogen reduction. On the other hand carbon dosing can reduce both.

Belgian Anthias
01/25/2018, 06:26 PM
I dont get what is the difference between being "skimmed out" and "being carried on the surface of the foam". What is skimmed out is also being carried on the surface of the foam, that his how a foam fractionator function. I dont think it matters that much as long as it ends up in the collection cup.

Skimmed means that a bound is made with an oxygen bubble. It is explained in the previous added link about skimming. It matters as not skim-able compounds accumulate in the system. It is good to know what ends up in the cup and what will not end up in the cup



Also for the 35% of total removed organic matter being bacteria, is that the value with carbon dosing or is the the amount removed in a tank w/o carbon dosing ? Because carbon dosing is known to significantly increase skimmer output. The increase is most likely bacteria or bacteria-based molecules.

Read the article about skimming and open links to the references.

Even than 35% is not a small number. I would actually expect the value to be a lot less. That is like 1.5% of removed organics is nitrogen inside bacteria. And like Bertoni pointed you dont have to remove intact bacteria, bacteria based products can also achieve this. Some bacteria that gets into foam will lyse before they can reach the collection cup, some will die or lyse within the tank and their contents will end up in skimmer. So you wont just have bacteria within the skimate, but the bacterial content. So the actual indirect export can be a lot higher. There would also be output from stuff like bacteria that is being consumed by other organisms (like bacteria ->copepod->fish). In my experience carbon dosing increase copepod populations, which indicate nitrogen in these bacteria can end up in a variety of different members of an aquarium. And from there nitorgen can go to skimmer, like in fish poop form or continue to be recycled among the organisms. These indirect outputs would be something hard to measure, you can potentially dose carbon-14 ethanol or acetic acid and make a radioactive tracing to see how much of it end up in the skimmer, fish and etc. and extrapolate a rough number for nitrogen (like 1 nitrogen atom for every 6 carbon atoms, which is the average ratio within a cell ). But I dont think anybody is doing or done this.




It means that minimum 65% may be recycled, A problem is that most of this 65% contain compounds that will not be skimmed, also not on a next passage true the skimmer, they accumulate. Activated carbon seems a lot more effective for removing DOC. But this has nothing to do with carbon dosing.

Yes, it becomes part of the food chain!

When I want to add something to a live support system I like to know what I am doing.
I do not like the fact that the carrying capacity support of system may become dependable of the dosing .
What is a good reason to add carbohydrates not knowing what may happen by doing so?
How difficult exporting nitrate may become?

I am not disagreeing that autotrophic nitrification is a lot more effective, but here I assume you are talking about sulfur based chemo-autotrophic assimilation. This is something I am very wary about the long term safety. I personally know someone whose tank nearly crashed to a sudden burst of H2S production. For an autotrophic assimilation nitrate process, using macro-algae or even mangroves is a lot safer.

by using SPC, I am talking about autotrophic nitrification and simultanious autotrophic and heterotrphic denitrification, not of autotrophic assimilation. Autotropic assimilation would not change much as growth is very slow compared to heterotrophs.

I have not suggested to use sulphur denitrators but SPC. Some sulphur denitrators are used and managed as they where heterotropic denitrators, which must be kept annoxic. These things are not safe for the short term safety when badly managed.

Sulphur denitrators are used with success in a lot of public and home aquaria since a few decades now. The oldest installations are used in the MAAO These systems, build following the guidelines of M Longouet, are NOT kept annoxic after start up. http://www.baharini.eu/baharini/doku.php?id=en:badess:bades:maao
Sulphur reactors must not be kept anoxic, Everything about BADES: http://www.baharini.eu/baharini/doku.php?id=en:badess:start

Sulphur can be used as base for growing a nitrifiying biofilm.

Is regular carbon dosing completely safe,of course no. It can cause bacteria blooms and suffocate the tank. It depletes some elements that we do not regularly test for (most notably potassium). But I have never heard anybody experiencing a sudden ammonia burst during carbon dosing. Considering carbon dosing is probably being done by thousands of people, lack of empirical evidence suggest it is not as likely as you suggest it to be.


Ammonia may build up when dosing is stopped, not while dosing, Nitrification does not take place when most ammonia is removed from the water column by dosing. Most bacteria present in the water column will deplete ammonium before using nitrate; this was explained at the opening of this threat. and the reason why this discussion was started. Reinstalling the nitrification capacity takes time.

When using SPC I know what I am doing; I know the side effects and how I can avoid them. Nitrogen is exported. No capacity shift.

And all in all there is one major problem. What you describe can only reduce nitrate but not phosphate. So you need an additional mechanisms to control phosphate, likely GFO or aluminum based absorbents. When you add these do the mix, it generally make the system phosphate limited and would effectively reduce the efficiency of nitrogen reduction. On the other hand carbon dosing can reduce both.



SPC will export nitrogen, not recycle it, without influencing the carrying capacity balance


When using GFO one can control the phosphate removal rate if it is used in a reactor. As phosphate is a limiting factor for the survival off all live, I rather would have some control over the removal rate. How depletion of phosphate is prevented using carbodosing as it is based on the nitrate level? One can do it biologically by activating phoshate accummulating organismn (PHO) http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:filtratie:bpr
.

Why make it difficult?

Belgian Anthias
01/25/2018, 06:40 PM
Have your research papers appeared in a peer reviewed journal? If so, would you mind providing their citation please?

Thank you.

All our research is written down in our wiki Makazi Baharini. Links to the wiki are used in this threat.
We are hobbyists and did the research for personal use.
Comments can be made below each article.

Belgian Anthias
01/25/2018, 07:12 PM
Dieter Brockman, one of the driving forces behind the Berlin method, said in an interview with Roger Vitko in 2004: "The Internet is as much a curse to hobbyists as it is a blessing. It contains many false statements and poorly thought out hobbyist "experiments" that are accepted as fact.

Keeping that in mind I try to use the knowledge available to make decisions.

I have no doubt that carbon dosing does shift the ammonia reduction capacity from nitrification to assimilation and that the carrying capacity of the system may become dependable of the dosing of carbohydrates.

I shared the information on which I have based myself to conclude that it may create a dangerous situation when for some reason carbon dosing is interrupted.

Al the other caveats which may or may not exist, it does not matter .

And for those who use it, the dosed should be matched with what is added to the aquarium and what is used by the aquarium and not only on nitrate present in the system

Belgian Anthias
01/29/2018, 08:25 AM
For those who want to know more about carbon dosing may be interested in the Biofloc technology.
Biofloc was introduced in the seventies in France and the technology was further developed and used worldwide for aquaculture and in ZMAS. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:filtratie:biofloc
Managing aquaculture systems by carbon dosing has no secrets any more. New detection technology introduced a lot of new players in de pocess but basically not much has changed.

All aquaria are aqua culture systems but few aquaculture systems are managed as it where aquaria as the purpose of use is completely different.

Biofloc technologie can be introduced in refugia, used as biofilter and for feeding. http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:filtratie:biofloc

Dan_P
01/30/2018, 07:19 PM
Nice presentation on biofloc technology.

https://cals.arizona.edu/azaqua/ista/ISTA9/PDF's/Yoram-BFT%20Brief%20Summary%205.3.11.pdf

The photomicrographs of biofloc in this presentation look very similar to solids collected by my skimmer. I started to examine skimmer solids after starting carbon dosing but at this time can’t conclude anything from preliminary observations. The only thing different is that I had to decrease air flow through the skimmer to maintain a reasonable flow of foam, otherwise I’d have a lot of skimmate on the floor :-).