Sulphur in the reefaquarium

[Belgian Anthias]

In anoxic zones where anaerobic mineralization takes place and enough nitrate is available denitrification takes place

organic + 124 NO3– + 124 H+ → 122 CO2 + 70 N2 + 208 H2O

Looking to this formula one can see that more nitrogen is exported as present in the amount of nitrate used. The nitrate removal depends on the availability of organics, of DOC. Nitrogen present in organics is needed and used up. What happens with the rest? The formula is very basic.

OM + 104HNO3 → 106CO2 + 60N2 + H3PO4 + 138H2O;
This is an other basic formula of the same process based on the phosphate production. What happens with produced phosphate and all other elements , the result of mineralization of organics? No nitrogen is left over to use everything up.
And what happens if not enough DOC is available to use up available nitrate?

it is simplistic to talk about anaerobic remineralisation as if it is about one process only. Nature has arranged it that in normal circumstances essential processes can go on. Where heterotrophic denitrification takes place, also DNRA takes place. The one is not without the other. Part of available nitrate is transformed back to ammonia, delivering the nitrogen source for new growth, NO3-→NO2- → NH4+
Usually DNRA accounts for about 15% of the total nitrate reduction, DNRA plus denitrification. (This must be enough to compensate for the nitrogen removed from minerelized organics for denitrification.) However, the ratio depends on the circumstances. and can exceed denitrification having high DOCavailability. GiblinEnCo2013)
Something to keep in mind when using carbon based denitrators.

Denitrification removes nitrogen from the system. DNRA keeps nitrogen in the system. Using carbon based denitrators most nitrate may be removed but a lot of ammonia may be produced.

The denitrification capacity depends on many factors and is autotrophic + heterotrophic, there is no winner.
At high nitrate levels heterotrophic denitrification will limit and outperform autotrophic denitrification and nitrate export is then related to DOC availability in anoxic zones.

In normal circumstances nitrate is used up for importing organic carbon, for photo-autotrophic growth, phytoplankton and algae . In most reef aquaria this balance is not maintained.

Heterotrophic growth exports carbon. Each heterotrophic cycle less carbon becomes available for fast growth and more ammonia must be nitrified. That is why heterotrophic growth must be compensated with autotrophic growth importing carbon, preventing nitrate build up.

Natural denitrification is a minor process .

 

[Randy Holmes-Farley]

Of course not enough organic is present in many tanks to drive complete nitrate removal. That us why organic carbon dosing works.

 

[Belgian Anthias]

Of course not enough organic is present in many tanks to drive complete nitrate removal. That us why organic carbon dosing works.

Stimulating heterotrophic growth in a reef aqyarium using carbohydrates, vodka, has been discussed and it may kill corals if overdosed. High DOC has been shown to be a lot more dangerous for corals compared to high nitrate and Phoshate availabilty. Adding organic carbon does not remove a thing, it stores nitrogen, it does not export nitrogen.

In ZMAS , being 0 emmision heterotrophic based aquaculture systems, heterotrophic growth is consumed and harvested, it is not exported by a natural process.

Adding organic carbon for stimulating heterotrophic denitrification, for exporting nitrogen, is not a good idea. , it will increase DNRA , producing more ammonia as exported by denitrification. To work, nitrate must be able to reach anoxic zones. Nitrate is safely stored nitrate, ammonia is toxic.

I am talking about normal aquarium conditions. Normal is having a low nitrate nitrate level due to having normal natural export combined with a balanced natural carbon import, consuming nitrate. Maintaining a balance between what is going in with what is going out.

High nitrate levels is an abnormal condition caused due to bad management. The balance between heterotrophic and autotrophic growth is not present. Good nitrogen management starts with the C/N ratio of food added.


Providing elemental sulfur will increase the natural nitrate export of nitrate produced in a biofilm growing on it, using it as a substrate. No need for anoxic conditions or H2S production .

 

[Randy Holmes-Farley]

I do not agree that dosing acetate has ever been shown to be dangerous to corals in an aquarium with sufficient N and P.

I did it for years and was very happy with it. You are just theorizing about problems that reefers do not experience.

 

[Belgian Anthias]

I do not agree that dosing acetate has ever been shown to be dangerous to corals in an aquarium with sufficient N and P.

I did it for years and was very happy with it. You are just theorizing about problems that reefers do not experience.

What problems? Only talking about natural processes taking place. A reefer knowing how to mange this processes will experience the difference. Adding some elemental sulfur will make a difference.

You do know everything is well documented. And dosing carbohydrates the way it often is advised does not prevent overdosing. A heterotrophic system is created having a huge effect on the coral holobiont. Also when using acetate .
A reefer will expierence it when it is too late and it will not be those who advised it who will explain the possible connection. Ignoring the possibility dosing organic carbon may create problems is bad advise.

In this threat we talk about denitrification. and the role of elemental sulfur; in a marine aquarium. As explained or having it your way, theorized, organics ( organic waste) are needed for heterotropic denitrification. Anaerobic Bacteria brake down organic waste to retrieve the carbon for energy and export all nitrogen left over, needing nitrogen present in the organic waste to use nitrate. Adding acetate will cause bacteria to use elements already present and will prevent organic waste present in anox zones to be reminerelized properly. Heterotrophic dentrification removes nitrate and produces a lot of phosphate wich can not be reused for new growth because the nitrogen needed is removed. Of coarce this is only a well documented theory.

Very bad idea messing up the natural balance in anoxic zones, by adding acetate or any other source of carbohydrates.

 

[Randy Holmes-Farley]

Say what you will, but acetate is a key player in natural carbon cycling, both in aerobic and anaerobic environments. Adding more acetate just facilitates this natural process.

 

[Belgian Anthias]

Say what you will, but acetate is a key player in natural carbon cycling, both in aerobic and anaerobic environments. Adding more acetate just facilitates this natural process.

It does!

The same time it is responsible for eliminating or limiting other essential natural processes. Adding more will have consequences.

Adding carbohydrates does NOT facilitates natural anaerobic and aerobic remineralization. it only facilitates heterotrophic growth. Bacteria do not have the need for braking down organics to retrieve carbon if free carbon is made available.

Can be used for stimulating denitrification in a wast water plant, where other processes are less important or may be ignored.

Nitrate and sulphate will be used as an oxygen source but the elements produced by anaerobic remineralization needed for autotrophic H2S oxydation will have been used up by heterotrophs due to adding acetate. How much acetate may be added? How preventing nitrate present in anoxic zones is used up producing a lot of H2S? A problem most reefers will not experience exempt when adding carbohydrates for facilitating denitrification.

In a normal biofilm all processes are in balance, promoting heterotrophic growth by adding free organic carbon will remove the balance.


As explained heterotrophic denitrification exports not only nitrate but also the nitrogen present in organic waste, leaving phosphate to accumulate.

Of coarse organic carbon availability plays an important role .. The question is if one does add it , how much? Based on what parameter?

In a reef aquarium I do prefer to maintain a balance between consumers , reducers and producers, as does a coral, in which organic carbon plays a key role. There is nothing wrong in managing the carbon content taking in account it will have a huge effect on the natural balance present in the aquarium. In a coral holobiont the balance is based on autotrophic growth and energy production, growth largely influenced by organic carbon availability, by growth dominance.

Adding organic carbon to reef aquarium water based on an abnormal nitrate content is a very bad idea, certainly if it is for stimulation denitrification.

Exporting safely stored nitrate-nitrogen even when doing it correctly it does not solve a thing, it does not correct the unbalance between reducers and producers. Good nitrate management starts at the source.

 

[Randy Holmes-Farley]

If you are worried about dosing vinegar, don't do it. If you hear of someone with an actual problem from dosing it, I'd like to hear about it.

I will continue to advise folks that it's a fine, natural approach to several problems, including elevated nitrate and boosting food to filter feeders when sufficient N and P is available.

 

[Belgian Anthias]

If you are worried about dosing vinegar, don't do it. If you hear of someone with an actual problem from dosing it, I'd like to hear about it.

I will continue to advise folks that it's a fine, natural approach to several problems, including elevated nitrate and boosting food to filter feeders when sufficient N and P is available.

How much is sufficient? On what parameter ?

How N is determined? Heterotrophic bacteria use mainly NH3-N . How overdosing is prevented?

What problems may be solved adding carbohydrates? What problems are created? Is one problem replaced by an other.

Changes the carbon availability and C/N ratio is easily done by correct feeding, The bacteria have no free carbon and the remineralisation process can go on. Overdosing is NOT possible.

A tank has a daily nitrate overproduction of 0. 05 ppm nitrate. Over time the nitrate level has increased to be 20ppm. Phosphate is 0.2 ppm. The target a nitrate level of 2ppm.
If the nitrogen is removed by heterotrophic growth facilitated by dosing organic carbon. How phosphate starvation , causing bleaching, is prevented? What is the advise? Who takes the responsibility?
Are reefers also advised about the conesquences if they want to stop dosing.

If there is a good reason to dose carbon I advise to do it in a refuge, not in a tank containing corals, and make shure all free carbon is used up before the water returns to the tank. Doing it this way heterotrophic growth ( bio-floc) can be harvested exporting a nutrients or used as food source. Symbiodinium will tank you for it.

 

[Belgian Anthias]

Elemental sulfur plays a minor but essential role there where anaerobic remineralization takes place.
We try to avoid anoxic conditions limiting the need for anaerobic H2S oxidation. In practisch we can not avoid it because the conditions are created everywhere in the tank where organics are reminerelized due to the high BOD demand of these processes. We do understand what is going on;

Adding some elemental sulfur to the tank will increase the natural nitrogen export rate, without Phosphate is produced and without messing up the existing balans because it only will remove what is already present, it will not steal nutrients needed elsewhere.

 

[Randy Holmes-Farley]

I dosed vinegar primarily for 2 reasons. Both seemed to be satisfied in my tank.

One was to reduce the amount of electricity spent growing macroalgae as nutrient control.

The second was to supply food for filter feeders, such as sponges. The foods include the acetate directly and the suspended bacteria.

I tried many doses over time. I did not experience apparent problems except at very high doses.

 

[Belgian Anthias]

I dosed vinegar primarily for 2 reasons. Both seemed to be satisfied in my tank.

One was to reduce the amount of electricity spent growing macroalgae as nutrient control.

The second was to supply food for filter feeders, such as sponges. The foods include the acetate directly and the suspended bacteria.

I tried many doses over time. I did not experience apparent problems except at very high doses.

I do not believe this. if one has a problem paying the electricity bill , I would not start with this hobby.

The electricity is well spent. Prevention of day-night pH fluctuations. .Periphyton and bio-floc will provide all the food needed, and not only for filter feeders. No need for very expensive products for treating the side effects of bad nutrient management. Very little negative side effects. And the carrying capacity needed can be pre-installed, before entering expensive life stock.



Acetate is free carbon. The filter feeders, managing their own holobiont, corals, sponges, I think they will not like there household is messed up by providing free carbon. But no problem if the pollution is removed, the vinegar is used up before the water is reentered in the display tank.


What is a very high dose? Based on what symptoms ( problems) or parameters it was determined a very high or too high dose is used? Can it be measured or does it show? If it shows, how the connection is made? If it shows, the harm is done. The side effects of dosing carbohydrates are well documented, How overdosing may be prevented?

Prevention is better than cure. Why take avoidable risks?

Nitrate is not considered by me as a problem, as a disease. In many cases, the treatment of the so-called problem carries more risk for problems caused by the side effects of the cure than the presence of safely stored and useful nitrate-nitrogen has ever been reported and confirmed.

It is of little use to treat the fever alone if one does nothing about the disease which causes the fever.

About denitrification:
It for sure will have a huge effect on BOD ( growth x 40) and change the composition of biofilms. It will for certain have an influence on the creation of more anoxic zones. Since the nitrate production is drastically reduced, this will have an impact on the H2S production in the biofilm and on the natural export of nitrogen, on the total denitrification capacity and DNRA.

Nitrate already present in the water does not penetrate very well and must mainly be removed by autotrophic growth, importing carbon.
Phytoplankton is the primary food source , heterotrophic dino's scavenge on bacteria.

 

[Randy Holmes-Farley]

I do not believe this. if one has a problem paying the electricity bill , I would not start with this hobby.

You do not believe it? I hardly even know what to say except I see no reason to continue to participate in this discussion.

 

[Belgian Anthias]

You do not believe it? I hardly even know what to say except I see no reason to continue to participate in this discussion.

I hope the open questions will be answered and be added in providing advice on how to prevent nitrate build-up and safely dispose of unused nutrients if necessary, taking into account the risks associated with the advice.

If in an autotrophic based closed marine system the carrying capacity fails , one is able to correct the situation very fast.
If in a heterotrophic based closed marine system the carrying capacity fails, one has one solution, remove the live stock as fast as possible.

 

[Dule T&T]

A lot of research has been done about the use of sulphur for denitrification ( BADES), meanly for to be used in water treatment plants for waste water and the treatment of groundwater for drinking water. Systems using sulphur for this purpose are now called SLAD systems, due to the fact limestone is added.. A decade before SLAD ( 2004) was introduced, sulphur and limestone ( maerl) was used for the removal of nitrate in marine aquarium systems in France. After 7 years of lab tests ( Longouet), the first public aquarium where BADES was used is MAAO ( 1996), as far as I know the installations where still operational in 2015.

Others followed. The Aquarium of Rochelle will decide to use BADES ( biological autotropic denitrification on elemental sulphur) in all installations in 2007 based on the work done by Fusari at the aquarium, published in 2007 . A lot of research is done this century about the application of BADES in aquaculture systems and ZMAS. There is not much about BADES which is not known and thoroughly tested.

One may conclude BADES is safe to use in a marine aquarium!

BADES is commercialized as a denitrator for home aquaria named "sulphur denitrator". These "sulphur denitrators" are, when used the same way a carbon based denitrator is used, very effective at high nitrate levels but have very poor results at low nitrate levels ( the same daily production of nitrate must be removed daily) . Most users try to keep the reactor anoxic for some reason which limits the flow drastically. This makes these devices also very susceptible and sensitive for mismanagement. For this reason not advisable for to be used in a live support system.
Most problems with so called "sulphur denitrators" of which I know about where caused by the way they where managed.

Why a "sulphur denitrator" must be kept annoxic? It was known and published in 1997 that BADES works fine in MAAO at a DO level of 3ppm. BADES works fine in a denitrator at flow rates of 5-10 X the volume of the sulphur, by 2-4 x the total system volume each day using a 1% reactor depending of the nitrate level and the amount of nitrate to remove daily. There is no need for the reactor to be kept anoxic. A BADES-reactor works fine as a denitrator and is very reliable! Using a BADES-reactor it is possible to close the nitrogen cycle while keeping the desired nitrate level.


it is known that when Elemental Sulphur is used as a base and substrate for a growing nitrifying biofilm + 90% of the ammonium reduced by nitrification may be removed and full nitrification may be achieved. This makes BADES very easy and safe to apply.

Mixing some elemental sulphur with aragonite sand as a base for a growing nitrifying biofilm should be enough to prevent nitrate to build up. The nitrate level in the system can easily be adjusted when used in a refuge or a reactor. The desired nitrate level can be maintained at any bio-load .

The answer is "True"

I am trying to get a straightforward answer.
Would use of sulfur media (in any way) in reef tank increase the amount of sulfur/sulfate in the system if we don't do water changes and how would that affect reef tank?
Because if with usage of sulfur I still need to perform water changes than it makes no sense to use it in a first place. The whole purpose of using sulfur denitrator (aerobic or annoxic) is to eliminate the need for tedious and expensive water changes - especially on large systems like mine - 500 gallons.

 

[Randy Holmes-Farley]

I am trying to get a straightforward answer.
Would use of sulfur media (in any way) in reef tank increase the amount of sulfur/sulfate in the system if we don't do water changes and how would that affect reef tank?
Because if with usage of sulfur I still need to perform water changes than it makes no sense to use it in a first place. The whole purpose of using sulfur denitrator (aerobic or annoxic) is to eliminate the need for tedious and expensive water changes - especially on large systems like mine - 500 gallons.

Certainly it will boost sulfate. But the effect is small against the massive natural background of 2700 ppm sulfate.

100 ppm of nitrate consumed adds 129 ppm of sulfate. That’s a 5% boost. Long term it may be an issue, but other additives may counteract it, such as calcium or magnesium chloride.

 

[Dule T&T]

Certainly it will boost sulfate. But the effect is small against the massive natural background of 2700 ppm sulfate.

100 ppm of nitrate consumed adds 129 ppm of sulfate. That’s a 5% boost. Long term it may be an issue, but other additives may counteract it, such as calcium or magnesium chloride.

I've been reading somewhere (it could be this portal actually, I can't remember) that some people had a little bit of cyanobacteria outbreak after they started using Sulfur denitrator.
Someone shared some research that says that cyano can deplete sulfates in the water.
Could cyanobacteria be some kind of indicator of possible elevated sulfate levels? Should we pay attention to it?

 

[Randy Holmes-Farley]

I've been reading somewhere (it could be this portal actually, I can't remember) that some people had a little bit of cyanobacteria outbreak after they started using Sulfur denitrator.
Someone shared some research that says that cyano can deplete sulfates in the water.
Could cyanobacteria be some kind of indicator of possible elevated sulfate levels? Should we pay attention to it?

No, sulfate is so high already that it is actively excluded from the interior of all organisms, even those that might use it as a source of sulfur. It does not drive Cyanobacteria.

Cyano will not

 

[Belgian Anthias]

I am trying to get a straightforward answer.
Would use of sulfur media (in any way) in reef tank increase the amount of sulfur/sulfate in the system if we don't do water changes and how would that affect reef tank?
Because if with usage of sulfur I still need to perform water changes than it makes no sense to use it in a first place. The whole purpose of using sulfur denitrator (aerobic or annoxic) is to eliminate the need for tedious and expensive water changes - especially on large systems like mine - 500 gallons.

Only if the sulfur denitrator is able to remove THE DAILY NITRATE OVERPRODUCTION at the desired low nitrate level. Using a reactor which is kept anoxic it is not possible to increase the flow in function of the nitrate level and the daily nitrate removal rate.

For example: to remove a daily nitrate production of 1ppm keeping the nitrate level at 2ppm 250 gal of water must be able to pass true the reactor daily. For this you would need a BADES reactor having a volume of at least 5 gallons. This is not possible using a sulfur denitrator keeping the reactor anoxic.

Only if a high daily nitrate production must be exported by autotrophic denitrification using elemental sulfur, BADES , sulfate may build up.
Normally, if using BADES the calcium media is replaced on a regular base and most produced sulfate, bound to the media, will be removed. It may take many years before Sulfate may become a concern, needing a big water change.

There is no need for an anoxic reactor to make good use of the BADES proces!

Normally ( not using a sulfur denitrator) autotrophic denitrification uses sulfur compounds, as H2S , H2S produced due to sulfate reduction, and transforms this H2S back to sulfate and some elemental sulfur. if H2S is not available produced elemental sulfur will be used and transformed back to sulfate, where the sulfur came from. The circle is closed.

A nitrate problem is not solved by using a denitrator and or performing water changes. If there is a nitrate problem, nitrate is safely stored and usable nitrogen, what problem are you talking about?

If nitrate accumulates this means for some reason there is no balance between reducers, bacteria braking down organics, and producers, photo-autotrophs producing organics. The circle is not closed.
Why available usable nitrate-nitrogen is not used up?

Nitrogen management starts with what is added to the tank.
Starting with the food added daily. High protein feed will result in high nitrogen availability, much more as heterotrophs, the consumers of the food, will need. More as the reducers, the bacteria braking down the waste, will consume. All nitrogen not used by consumers and reducers stays available as ammonia and normally this toxic ammonia is transformed by nitrifiers into a safe form of usable nitrogen, nitrate. This way solving the problem of toxic ammonia. Calling the presence of nitrate a problem one must have a very good reason.
This safely stored but usable nitrogen is then available for slower growing organisms, the producers. Restoring the natural balance all available nitrate-nitrogen will be used up. ( if not using a skimmer)

Nitrogen management starts with knowing what is going in .

If one has a fever putting ice on your forehead will not cure the disease causing the fever.