Why don't we know how much biomass is exported? Even public and commercial aquariums don't know?
Reflects before you begin dosing carbohydrates
- Thread starter Belgian Anthias
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Why don't we know how much biomass is exported? Even public and commercial aquariums don't know?
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.
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.
Me too.
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.
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.
Belgian Anthias
New member
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
New member
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.
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Belgian Anthias
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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.
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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.
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Belgian Anthias
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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).
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Belgian Anthias
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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
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.
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.
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.
You've posted that paper before. I still don't understand the relevance. What are you trying to say?
1) "œAll this implements a very low nitrification and denitrification capacity."
2) "œAn 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) "œOnce 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 "œnever 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
2) "œAn 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) "œOnce 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 "œnever 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
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.
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
New member
Respiratory Nar system
Respiratory Nar system
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.
Respiratory Nar system
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.
