Sulphur in the reefaquarium

[Belgian Anthias]

Sulphur must have been very important in forming the oceans as there is a lot of it, mostly present as sulphate. But this sulphate content seems not to be very important for keeping reef aquaria as salt mixes do vary a lot in sulphate content. https://reefhub.pl/test-of-marine-salts/
Elemental sulphur is only present in very small amounts in the aquarium although in the ocean it is present everywhere, sometimes in huge amounts, as at the coastline of Chili where several million tons are present on the bottom of the sea, playing an important role in the nitrogen and carbon cycle in the ocean.
What is the role of sulphur in a reef aquarium? How important is sulphur for the nitrogen cycle?

In a normal nitrifying biofilm +- 40% of the population have an anaerobic pathway, living in the oxygen minimum zones and anoxic zones, occupied recycling and renewing the biofilm. In the nitrifying biofilm, heterotrophic denitrification is limited due to the limited availability of anoxic zones and of the availability of organic carbon in those zones. Autotrophic denitrification is limited due to the limited availability of usable sulphur in the oxygen minimum zones and anoxic zones.

It is known that if a nitrifying biofilm grows on elemental sulphur more than 90% of the NH4 reduced by nitrification may be removed as nitrogen gas. By providing elemental sulphur as substrate a nitrifying biofilter may produce very little nitrate but a lot of nitrogen gas. This way the nitrogen is effectively removed . The process responsible for this is BADES, Biologaical Autotropic Denitrification on Elemental Sulphur.

Just by providing some elemental sulphur the aquarium system is able to close the nitrogen cycle!

True or false?

 

[Larry L]

I don't have any answers but it's a very interesting question, following...

 

[Cory]

I was just reading about this today in randys article sulphur.

There are proven filters that remove no3 with elemental sulphur beads. I had one and it worked very well.

I imagine using elmental sulphur beads in the place of an old style bio ball tower would do the trick! Work it the same way too trickle the water over the beads.

 

[Dan_P]

I was just reading about this today in randys article sulphur.

There are proven filters that remove no3 with elemental sulphur beads. I had one and it worked very well.

I imagine using elmental sulphur beads in the place of an old style bio ball tower would do the trick! Work it the same way too trickle the water over the beads.

Why do you think carbon dosing caught on but not sulfur beads to remove nitrate?

 

[Cory]

Why do you think carbon dosing caught on but not sulfur beads to remove nitrate?

Good question. I got rid of mine 10 years back because those bright yellow beads scared the **** out of me lol. Probably people think they add stuff to the water. Much like marine pure bricks are a fad now but we realize now they leach aluminium. Not only that iirc they reduce alk too.

 

[Dan_P]

Sulphur must have been very important in forming the oceans as there is a lot of it, mostly present as sulphate. But this sulphate content seems not to be very important for keeping reef aquaria as salt mixes do vary a lot in sulphate content. https://reefhub.pl/test-of-marine-salts/
Elemental sulphur is only present in very small amounts in the aquarium although in the ocean it is present everywhere, sometimes in huge amounts, as at the coastline of Chili where several million tons are present on the bottom of the sea, playing an important role in the nitrogen and carbon cycle in the ocean.
What is the role of sulphur in a reef aquarium? How important is sulphur for the nitrogen cycle?

In a normal nitrifying biofilm +- 40% of the population have an anaerobic pathway, living in the oxygen minimum zones and anoxic zones, occupied recycling and renewing the biofilm. In the nitrifying biofilm, heterotrophic denitrification is limited due to the limited availability of anoxic zones and of the availability of organic carbon in those zones. Autotrophic denitrification is limited due to the limited availability of usable sulphur in the oxygen minimum zones and anoxic zones.

It is known that if a nitrifying biofilm grows on elemental sulphur more than 90% of the NH4 reduced by nitrification may be removed as nitrogen gas. By providing elemental sulphur as substrate a nitrifying biofilter may produce very little nitrate but a lot of nitrogen gas. This way the nitrogen is effectively removed . The process responsible for this is BADES, Biologaical Autotropic Denitrification on Elemental Sulphur.

Just by providing some elemental sulphur the aquarium system is able to close the nitrogen cycle!

True or false?

Are you refering to sulfur denitrators or sulfur reactors?

 

[Dan_P]

Good question. I got rid of mine 10 years back because those bright yellow beads scared the **** out of me lol. Probably people think they add stuff to the water. Much like marine pure bricks are a fad now but we realize now they leach aluminium. Not only that iirc they reduce alk too.

Was this system refered to as a sulfur reactor or sulfur denitrator?

 

[Cory]

Was this system refered to as a sulfur reactor or sulfur denitrator?

Its purpose was to reduce nitrate at a slow flow. Iirc it was a denitrator. Whats the difference? I hadnt heard of a sulphur reactor.

 

[Dan_P]

Its purpose was to reduce nitrate at a slow flow. Iirc it was a denitrator. Whats the difference? I hadnt heard of a sulphur reactor.

Not sure there is a difference. I just provided the two names I found associated in Google search on “sulfur to denitrify water”.

Was the system tricky to use?

 

[Cory]

Not sure there is a difference. I just provided the two names I found associated in Google search on “sulfur to denitrify water”.

Was the system tricky to use?

No actually was just set it and forget it. I just had to make sure the flow rate was right.

 

[Belgian Anthias]

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"

 

[Dan_P]

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"

What is keeping this approach from becoming more popular?

 

[Belgian Anthias]

What is keeping this approach from becoming more popular?

Maybe because one is not interested as it is not generally known what sulphur may contribute to the management of a marine aquarium and how it can be used in favour? The use of sulphur is not promoted .
Maybe because sulphur has a bad name which is spread around without any verification or further consideration? A bit as the banning of the biofilter. Badly managed bio-filters produce more nitrate as necessary? Some advised to removed the bio-filter instead of doing the effort to search for and correcting the reason why, probably because they where not aware there bio-filter was not managed correctly..Now it is generally accepted the use of a biofilter produces to much nitrate which is of coarse not true if properly managed. The only thing what is changed is the fact that the carrying capacity and the max bio-load of the marine aquarium system can not easily be adjusted any more and is fiercely reduced . This only in the marine aquarium business! What would an aquaculture system be without bio-filters!?
An aerobe biofilter which contains elemental sulphur ( BADES biofilter) will reduce ammonia while producing nitrogen gas, limiting the nitrate production to a very small amount.

As far as I know the only application of BADES which has been discussed in the marine aquarium trade is the use in a denitrator. Accompanied by the advice to try to keep the reactor anoxic. Where this comes from I do not know exactly as the pioneers of the use of BADES in marine aquarium systems never gave the advice to keep sulphur reactors anoxic after start up. . Of those who tried it the anoxic way a lot where very disappointed as this method is very vulnerable to human error, certainly when using a to small reactor which is often the case. Wrong management gave the use of sulphur denitrators a bad name and the failure was often connected to the unconfirmed fact it must have been the sulphur.
It is known that if a BADES reactor is managed properly it works fine, is very reliable and becomes self-regulating. A BADES-reactor is NOT kept anoxic.
Any way, it must be clear that I do not promote the use of Sulpur denitrators the way it is generally promoted to use them for the reasons I explained. Such "Sulphur denitrators" will not be advised by me for to be used in a live support system.

Maybe because it is commercially not very interesting as adding some cheap sulphur may replace a shelf of commercially more interesting products? Sulphur is consumed very slowly, depending of the activities on it it may take years.

 

[Belgian Anthias]

More information about using BADES columns, a method I prefer for using BADES.

 

[Randy Holmes-Farley]

I'm not a fan of sulfur denitrators since they deplete alkalinity, but they are certainly an acceptable way to reduce nitrate if elevated nitrate is an issue in your aquarium.

I personally prefer carbon dosing since it is neutral toward alkalintiy, and the dosed organics can be used by a wide range of organisms, including corals, rather than specialized sulfur bacteria.

 

[Randy Holmes-Farley]

Maybe because one is not interested as it is not generally known what sulphur may contribute to the management of a marine aquarium and how it can be used in favour? The use of sulphur is not promoted .

I certainly detail how it works in my nitrate articles, but no, I do not "promote" it as I think there are better alternatives.

For example:

Nitrate in the Reef Aquarium - REEFEDITION
http://www.reefedition.com/nitrate-in-the-reef-aquarium/

from it:

Sulfur Denitrators

In these systems, bacteria use elemental sulfur and produce N2 from the sulfur and nitrate according the following equation (or something similar):

2 H2O + 5 S + 6 NO3– → 3 N2 + 5 SO42- + 4 H+

The production of acid (H+) in this reactor can tend to reduce the aquarium alkalinity. It has also been suggested to pass the effluent of such a reactor through a bed of aragonite to use the acid (H+) produced to dissolve the calcium carbonate, and thereby provide calcium and alkalinity to the aquarium. While that is a fine idea, it doesn’t add much calcium and alkalinity to most aquaria.

To estimate the magnitude of the effect, we start with a liberal estimate of how much nitrate might be removed. Say 10 ppm of nitrate per week.

10 ppm nitrate = 0.16 mmole/L of nitrate

Since 4 moles of H+ are produced for every 6 moles of nitrate consumed, this will produce

0.107 mmoles/L of H+ per week

How much calcium this could produce?

Assume that it takes one proton to dissolve one calcium carbonate:

CaCO3 + H+ → Ca2+ + HCO3–

Clearly, this is a substantial overestimate because much of the acid will be used up driving the pH down to the point where CaCO3 can even begin to dissolve. Consequently, we have an upside limit of 0.107 mmoles of Ca2+ per week. Since calcium weighs 40 mg/mmol, that’s 4.3 ppm Ca2+ per week.

For comparison, an aquarist adding 2% of the tank volume in saturated limewater daily is adding on the order of 16 ppm of calcium per day. Consequently, this method may not be especially useful for maintaining calcium. Additionally, the acid produced will have a long term lowering effect on the alkalinity. In fact, it is double dipping on the alkalinity depletion since alkalinity is consumed when the nitrate is produced, and again when it is removed in the denitrator. So if you use a sulfur denitrator, be sure to monitor the alkalinity in the aquarium.

 

[Art2249]

I guess I don't need a de-nitrator since I have sulfur in my source water. Ugh.

 

[Belgian Anthias]

I'm not a fan of sulfur denitrators since they deplete alkalinity, but they are certainly an acceptable way to reduce nitrate if elevated nitrate is an issue in your aquarium.

I personally prefer carbon dosing since it is neutral toward alkalinitiy, and the dosed organics can be used by a wide range of organisms, including corals, rather than specialized sulphur bacteria.

I am also not a fan of using sulphur denitrators the way they are promoted! I certainly will not advice the use of such denitrators.

This is not about lowering elevated nitrate! It is about closing the nitrogen cycle and controlling the nitrate level on the desired level . I can not see the link with carbon dosing!

It is a fact that the net process of BADES reduces alkalinity as does nitrification and a lot of processes in an aquarium. It also produces sulphate. This does not mean the total alkalinity will be influenced in a way it is of any importance.
In a BADES system the denitrification part is performed by both heterotrophs (+- 15%) and autotrophs.

A BADES system will NOT deplete the total alkalinity in a marine aquarium as all H+ produced by the autotrophic nitrate reduction part is used up producing calcium and bicarbonate using the calcium carbonate made part of the BADES system (SLAD system T.C.Zhang 2004) ! Calcium carbonate is added as part of a BADES system at least since BADES is used in marine live support systems, at least since 1992! A lot of experience to relay on.
The effect on alkalinity of a BADES system was the subject of many different studies. Based on these studies and practical use during decades one may conclude the use of BADES does has minor effect on the total alkalinity in a marine aquarium system on the long term . Some of these studies are available for reading in our wiki Makazi Baharini.
As also H+ of the nitrification part taking place in a BADES biofilter will have little or no effect on alkalinity the total effect on alkalinity of a BADES biofilter may be considered to be neutral, even positive.
Calcium is produced by both nitrification and denitrification processes in a BADES bio-filter or reactor which may influence the calcium level, certainly in a fish only tank.

The impact on alkalinity of NH4 assimilation by photo-autotrops and heterotrops may be considered to be far more important.

All these processes take place in an aquarium as sulphur is produced constantly during the nitrate reduction process responsible for the reduction of the constantly produced HS. Produced HS is constantly reduced to sulphate and/ or elemental sulphur which is used for BADES. Without these specialized bacteria the aquarium would not look the same! This indicates the importance of the presence of nitrate and the presence of those specialized sulphur bacteria which are not promoted by the presence of an unnatural high C:N ratio. ! A nitrifying biofilm is a mix of many specialized bacteria working together.
Growing the biofilm on elemental sulphur promotes the growth of these specialized denitrifying bacteria increasing the denitrification capacity of the nitrifying biofilm considerably.

The application of BADES is not limited to the use in a denitrator!

It is a fact carbon dosing does not remove a thing from the aquarium. Most of the carbon added will end up as CO2.
Assimilation of NH4 does deplete alkalinity. We know that carbon dosing meanly promotes fast temporarily heterotrophic growth and NH4-N assimilation. NO3-N will only be used in case NH4-N is not available which means NH4-N may not be available during the log phase for slow growing organisms !
For each gram of NH4 incorporated into biomass 3.57 gram alkalinity is consumed and 9.65 gram CO2 produced. (Ebeling 2006)

Claiming carbon dosing is neutral for alkalinity seems to be incorrect!

Keeping on a high C:N ratio seems to be not that good for corals, as they are surrounded by specialized bacteria which the corals cultivate by providing the nutrients these bacteria need. Maintaining a high C:N ratio in the aquarium will outcompete these specialized bacteria. Corals are very selective in what they consume. Promoting carbon dosing as a food source for corals? Not by me!

Nitrification combined with dentrification removes nitrogen, availability of organic carbon keeps nitrogen in the system.. Nature limits the availability of organic carbon for a reason!

Anyway, carbon dosing has nothing in common with the subject .

What is the role of sulphur in the nitrogen cycle of an aquarium and how Sulphur may be used to have control over it? Or better, what is the role of nitrogen in the Sulphur cycle within an aquarium and how make better use of it.

Is it possible to prevent nitrate build up just by adding a certain amount sulphur grains to the aquarium?

Yes we can!

 

[Randy Holmes-Farley]

A BADES system will NOT deplete the total alkalinity in a marine aquarium as all H+ produced by the autotrophic nitrate reduction part is used up producing calcium and bicarbonate using the calcium carbonate made part of the BADES system (SLAD system T.C.Zhang 2004) !

lol

All that means is that you trade alkalinity depleting for calcium rising.

 

[Belgian Anthias]

I certainly detail how it works in my nitrate articles, but no, I do not "promote" it as I think there are better alternatives.

For example:

Nitrate in the Reef Aquarium - REEFEDITION
http://www.reefedition.com/nitrate-in-the-reef-aquarium/

from it:

Sulfur Denitrators

In these systems, bacteria use elemental sulfur and produce N2 from the sulfur and nitrate according the following equation (or something similar):

2 H2O + 5 S + 6 NO3– → 3 N2 + 5 SO42- + 4 H+

The production of acid (H+) in this reactor can tend to reduce the aquarium alkalinity. It has also been suggested to pass the effluent of such a reactor through a bed of aragonite to use the acid (H+) produced to dissolve the calcium carbonate, and thereby provide calcium and alkalinity to the aquarium. While that is a fine idea, it doesn’t add much calcium and alkalinity to most aquaria.

To estimate the magnitude of the effect, we start with a liberal estimate of how much nitrate might be removed. Say 10 ppm of nitrate per week.

10 ppm nitrate = 0.16 mmole/L of nitrate

Since 4 moles of H+ are produced for every 6 moles of nitrate consumed, this will produce

0.107 mmoles/L of H+ per week

How much calcium this could produce?

Assume that it takes one proton to dissolve one calcium carbonate:

CaCO3 + H+ → Ca2+ + HCO3–

Clearly, this is a substantial overestimate because much of the acid will be used up driving the pH down to the point where CaCO3 can even begin to dissolve. Consequently, we have an upside limit of 0.107 mmoles of Ca2+ per week. Since calcium weighs 40 mg/mmol, that’s 4.3 ppm Ca2+ per week.

For comparison, an aquarist adding 2% of the tank volume in saturated limewater daily is adding on the order of 16 ppm of calcium per day. Consequently, this method may not be especially useful for maintaining calcium. Additionally, the acid produced will have a long term lowering effect on the alkalinity. In fact, it is double dipping on the alkalinity depletion since alkalinity is consumed when the nitrate is produced, and again when it is removed in the denitrator. So if you use a sulfur denitrator, be sure to monitor the alkalinity in the aquarium.

When a nitrifying biofilm grows on a base of calcium carbonate the effect on alkalinity is completely compensated for! (Green En Co 2001 )

When chalk is mixed with elemental sulphur the BADES process will not consume alkalinity, producing calcium and bicarbonate
55S + 44CaCO 3 + 50NO 3- + 18H2O + 4NH4+ → 4 C5H7O2N + 25N 2 + 55SO4 2- + 44Ca 2+ + 24HCO3- ( T.C. Zhang 2004 ) The theoretical calcium production is shown.
10 ppm nitrate reduced by BADES may produce 5,68 ppm calcium. Using a BADES bio-filter or reactor calcium is also produced by nitrification.


The use of anoxic denitrators is not advisable for to be used in a life support system. BADES reactors are not kept anoxic!