Reflects before you begin dosing carbohydrates

[nogascans]

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]

Data always are interesting.

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

 

[Belgian Anthias]

biopellets

biopellets

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]

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]

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]

Thank you for the clarification!

 

[Belgian Anthias]

Pha

Pha

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]

Basics

Basics

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]

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]

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]

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]

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/fi...he proteins from E. coli cell supernatant.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]

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]

What? SPC method.

What? SPC method.

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]

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]

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]

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]

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]

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]

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