Reflects before you begin dosing carbohydrates

[Dan_P]

Originally Posted by bertoni

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]

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]

Originally Posted by bertoni

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]

Originally Posted by Tripod1404

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...iwitafschuimer

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...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]

Originally Posted by Dan_P

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...iwitafschuimer 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]

Have your research papers appeared in a peer reviewed journal? If so, would you mind providing their citation please?

Thank you.

[Tripod1404]

Originally Posted by Belgian Anthias

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]

Originally Posted by Tripod1404

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...ess:bades:maao
Sulphur reactors must not be kept anoxic, Everything about BADES: http://www.baharini.eu/baharini/doku...n: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...:filtratie:bpr
.

Why make it difficult?

[Belgian Anthias]

Originally Posted by DiscusHeckel

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]

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]

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...tratie: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...tratie:biofloc

[Dan_P]

Nice presentation on biofloc technology.

https://cals.arizona.edu/azaqua/ista...y%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 :-).