Reflects before you begin dosing carbohydrates

[Belgian Anthias]

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]

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]

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 "œtypical" 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]

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]

.

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 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]

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]

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]

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]

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]

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]

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]

Other concerns

Other concerns

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/dok...water:aoa_ammonium_oxiderende_archaeabacteria

 

[Belgian Anthias]

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 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 550:30:1, by maintaining the N 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]

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 "œintroduction", 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]

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]

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]

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]

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]

Conclusion

Conclusion

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]

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:bacteriën#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?