DSB in a bucket for nitrate control

[Reefin' Dude]

Both are just nutrient sinks. The ATS going after the decomposed waste organic material. The RDSB holding onto the waste organic material and releasing inorganic nutrients as the waste organic material decomposes slowly. In a way they work together. I prefer to just siphon away the waste organic material before it has a chance to decompose and be available to the inorganic nutrient removal device du jour.

G~

 

[Swope2bc]

Both are just nutrient sinks. The ATS going after the decomposed waste organic material. The RDSB holding onto the waste organic material and releasing inorganic nutrients as the waste organic material decomposes slowly. In a way they work together. I prefer to just siphon away the waste organic material before it has a chance to decompose and be available to the inorganic nutrient removal device du jour.



G~

Some may use these in place of good maintenance, but if you read about them you will see that the intent is not to promote poor cleaning habits, but rather to supplement them. They are also both quite reflective of the natural filtration provided in our oceans today. The RDSB, properly built, does not allow for detritus to settle. It is not the same as a standard DT or fuge DSB. An ATS provides a peace to promote healthy algae growth thereby discouraging that growth in the DT. A person should still perform regular maintenance and PWC. Just my .02.

 

[Swope2bc]

Both are just nutrient sinks. The ATS going after the decomposed waste organic material. The RDSB holding onto the waste organic material and releasing inorganic nutrients as the waste organic material decomposes slowly. In a way they work together. I prefer to just siphon away the waste organic material before it has a chance to decompose and be available to the inorganic nutrient removal device du jour.



G~

All of that being said, you definitely have more experience in the hobby than me (a noob)!

 

[Reefin' Dude]

Some may use these in place of good maintenance, but if you read about them you will see that the intent is not to promote poor cleaning habits, but rather to supplement them. They are also both quite reflective of the natural filtration provided in our oceans today. The RDSB, properly built, does not allow for detritus to settle. It is not the same as a standard DT or fuge DSB. An ATS provides a peace to promote healthy algae growth thereby discouraging that growth in the DT. A person should still perform regular maintenance and PWC. Just my .02.

Yes and No. If one looks at how nutrients are moved in the oceans, we are missing a very big component, mechanical removal of waste organic material. Not sure how or why the reef industry glosses over this part, but they do. Tides and tropical storms move any ocean substrates to depths far greater than what we have in our systems. This movement release and moves the waste organic material away. Out to the abyss. Where it enters another ecosystem. One that is not light dependent.

Detritus does not need to settle in on a substrate in order for a substrate to accumulate detritus. Substrates will create their own detritus form bacterial action on the aragonite. The bacteria are going to get their phosphates from somewhere (The bacteria necessary for converting nitrates need phosphate). The aragonite is going to absorb the phosphates. Once the bacteria have it, then the bacteria are not going anywhere. They are in the substrate. The organisms just keep getting bigger from there. All of that life in a substrate represents nutrients. All of those organisms need nutrients to live. All of those organisms also produce waste.

All i am suggesting is stir up the substrate every now and then and get all of that detritus out of there, and let the substrate start fresh again. Just like what happens in the oceans.

G~

 

[CuzzA]

Both are just nutrient sinks. The ATS going after the decomposed waste organic material. The RDSB holding onto the waste organic material and releasing inorganic nutrients as the waste organic material decomposes slowly. In a way they work together. I prefer to just siphon away the waste organic material before it has a chance to decompose and be available to the inorganic nutrient removal device du jour.

G~

Hmmm, this doesn't sound right. Is this from personal experience? How was your RDSB set up?

The RDSB is supposed to be fed with pre mechanical filtered water with sufficient flow to eliminate organic waste settling. So how, if setup properly, does it become a "nutrient sink" when the predominate thing in the water passing over the sand bed is nitrates? Where the nitrates are then converted to nitrogen gas and exported from the system into the atmosphere.

 

[Swope2bc]

Yes and No. If one looks at how nutrients are moved in the oceans, we are missing a very big component, mechanical removal of waste organic material. Not sure how or why the reef industry glosses over this part, but they do. Tides and tropical storms move any ocean substrates to depths far greater than what we have in our systems. This movement release and moves the waste organic material away. Out to the abyss. Where it enters another ecosystem. One that is not light dependent.



Detritus does not need to settle in on a substrate in order for a substrate to accumulate detritus. Substrates will create their own detritus form bacterial action on the aragonite. The bacteria are going to get their phosphates from somewhere (The bacteria necessary for converting nitrates need phosphate). The aragonite is going to absorb the phosphates. Once the bacteria have it, then the bacteria are not going anywhere. They are in the substrate. The organisms just keep getting bigger from there. All of that life in a substrate represents nutrients. All of those organisms need nutrients to live. All of those organisms also produce waste.



All i am suggesting is stir up the substrate every now and then and get all of that detritus out of there, and let the substrate start fresh again. Just like what happens in the oceans.



G~

These statements definitely make your previous comments much more clear and reasonable. When I read the first 50 pages (pre thread split) of this thread I became more and more frustrated with people constantly repeating the same questions or assuming that a RDSB could eliminate regular maintenance.

 

[Reefin' Dude]

Hmmm, this doesn't sound right. Is this from personal experience? How was your RDSB set up?

The RDSB is supposed to be fed with pre mechanical filtered water with sufficient flow to eliminate organic waste settling. So how, if setup properly, does it become a "nutrient sink" when the predominate thing in the water passing over the sand bed is nitrates? Where the nitrates are then converted to nitrogen gas and exported from the system into the atmosphere.

I no longer run sand my systems. I have tried every which way to run a DSB you could think of.

The DSB itself is going to create its own detritus. Those same bacteria that are converting the nitrates, need phosphates. All living organisms need phosphates. You are correct that N can be off gassed. P on the other hand can not. If there is N2 gas production going on, then there must be phosphates involved to keep the bacteria alive. You can not have one without the other. The phosphates initially come form the aragonite itself. It is virtually impossible to get any aragonite that does not have some P bound to it. The bacteria start off with these. They will continue to get more P from the water column from the decomposition of waste organic material in other areas of the system, and directly from organism excretion. Unfortunately there is just no way to keep detritus from accumulating in a substrate.

G~

 

[RocketEngineer]

Both are just nutrient sinks. The ATS going after the decomposed waste organic material. The RDSB holding onto the waste organic material and releasing inorganic nutrients as the waste organic material decomposes slowly. In a way they work together. I prefer to just siphon away the waste organic material before it has a chance to decompose and be available to the inorganic nutrient removal device du jour.

G~

If the RDSB is holding onto waste material, there isn't enough flow across it.

 

[RocketEngineer]

I no longer run sand my systems. I have tried every which way to run a DSB you could think of.

The DSB itself is going to create its own detritus. Those same bacteria that are converting the nitrates, need phosphates. All living organisms need phosphates. You are correct that N can be off gassed. P on the other hand can not. If there is N2 gas production going on, then there must be phosphates involved to keep the bacteria alive. You can not have one without the other. The phosphates initially come form the aragonite itself. It is virtually impossible to get any aragonite that does not have some P bound to it. The bacteria start off with these. They will continue to get more P from the water column from the decomposition of waste organic material in other areas of the system, and directly from organism excretion. Unfortunately there is just no way to keep detritus from accumulating in a substrate.

G~

The phosphate you are talking about is bound into the biomass of the bacteria on the sand. It's not floating around in the water column to be used by anything else in the system.

Removing nitrates is the singular goal of a Bucket DSB. The removal of phosphates or the accumulation of them has very little bearing on the workings of a properly set up Bucket DSB. With sufficient flow across the surface, biomass which becomes free floating is transferred into the water column and handled by other means within the system. If set up properly, a Bucket DSB should never become a "nutrient sink" of limited carrying capacity.

 

[Reefin' Dude]

If the RDSB is holding onto waste material, there isn't enough flow across it.

The amount of flow will not eliminate the accumulation of detritus. The DSB itself is creating its own detritus. If it did not, then the bacteria and other organisms would not have any resources to live. Organisms living in the DSB are a sign that there are resources necessarily for them to survive. Those organisms were not there when the DSB was put in there correct? How did they get there and what are they feeding on?

The phosphate you are talking about is bound into the biomass of the bacteria on the sand. It's not floating around in the water column to be used by anything else in the system.

Some of it is. Testable P and N are the inorganic nutrients floating around and are available to autotrophs. Where did the bacteria originally get the phosphates? If there is not an accumulation of the phosphates, then how can there be an increase in biomass of the bacteria? You can not have an increase in a biomass without also an increase in resources needed for that biomass, nor an increase in the amount of waste produced by the biomass. Meaning conversion of nitrates to N2.

Removing nitrates is the singular goal of a Bucket DSB. The removal of phosphates or the accumulation of them has very little bearing on the workings of a properly set up Bucket DSB. With sufficient flow across the surface, biomass which becomes free floating is transferred into the water column and handled by other means within the system. If set up properly, a Bucket DSB should never become a "nutrient sink" of limited carrying capacity.

You can not "remove" nitrates without P. The amount of phosphates has a big bearing on the removal of nitrates. One can not look at just N, one must also look P, C, or even H. We just like to fixate on N because it is easy. It means very little when looked at by itself, but means loads if looked at all of the major elemental pathways together. The same bacteria converting N need P. The more nitrates being converted the more P that must also be involved. You can not have one without the other.

Only the very top layers of a substrate are affected by flow enough to "pull" biomass out of a substrate. Unless large scale mechanical disruption or siphoning occurs. If all of the bacterial biomass was "pulled" up out of the substrate like suggested, then how are the nitrates being converted to N2? Don't they need to be in an anoxic environment? Wouldn't that mean lack of flow? How did the resources get down to a depth that this could occur if there was not an accumulation of detritus?

G~

 

[RocketEngineer]

I think you consider bacteria biomass to equate to detritus. To me detritus is pieces of food, molts, fish scales, dust and hair from outside the tank. This is the stuff that sits in a low flow spot and decomposes, releasing its nutrients into the water column in general. On the other hand, biomass is the film of bacteria, algae, and other microorganisms that coats every possible surface inside our systems. The materials that make them up are not generally released back into the water column for other organisms to use unless the bacteria is disturbed enough to cause it to be free floating itself. Then it gets used as food by another organism and so on.

Now, biomass will take up phosphate in order for the bacteria to multiply. In doing so they will remove that amount of phospates from the water column so that it is unavailable to anything else in the tank. By contrast, that same bacteria is taking up lots of nitrate, splitting the molecule into constituent parts, using the oxygen, holding onto the chemical energy for other processes, and releasing a molecule of nitrogen gas as the byproduct of this reaction. While the two are linked in that without the oxygen from the nitrate molecule the bacteria would be unable to utilize the phosphate, the true is the bacteria are utilizing a significantly higher volume of nitrate. This only occurs in a low oxygen environment because otherwise the bacteria would use the oxygen present and the nitrogen cycle would stop at nitrates being produced.

The point I want to make is that the bacteria are using the nitrate as an oxygen source and as such will utilize a much larger amount than they will use phosphates. There are a number of chemical reactions the bacteria is doing that do not require phosphate but do require oxygen.

 

[Reefin' Dude]

I consider all dead organic material detritus. This includes bacterial mulm, poo, and dead organisms.

Bacteria do not live forever. Like any organism, they do die. The P and N that they contain must go somewhere. What happens with those? If they are utilized by bacteria, then we must count those bacteria as part of the biomass and all of the resources needed to sustain them. It quickly becomes an ecosystem. All with an increase need for P. P does not go away. It must be physically exported. We are not lucky enough to have it off gas like the other elements. It accumulates.

What i am getting at is that if there is any increase biomass, then there must also be an in crease in P and N to support that biomass. If the point of a DSB is to convert nitrate to N2, then there must be a thriving biomass in the substrate to accomplish this. All of this biomass was not there when the substrate was installed. How did they get there? What is "fueling" it. All of this points to an increase in nutrients within the substrate. If there wasn't this increase, than the substrate would not increase its ability to accomplish its task of converting nitrates to N2. An entire system is not being supported by a single individual bacterium. It has friends. A whole lot of friends. Unfortunately a lot of those friends also die.

G~

 

[RocketEngineer]

I consider all dead organic material detritus. This includes bacterial mulm, poo, and dead organisms.

Ok agreed. On the same page.

Bacteria do not live forever. Like any organism, they do die.

Actually, bacteria theoretically do live forever because when they split, they are two copies of the original. Now, certain individuals will die, but this is mostly due to conditions changing where they live or some other organism killing them.

The P and N that they contain must go somewhere. What happens with those? If they are utilized by bacteria, then we must count those bacteria as part of the biomass and all of the resources needed to sustain them.

There is a big difference between bacteria sustaining their current population and bacteria that are growing their population. A bacteria only splits when it has enough materials and energy to do so. They still use oxygen even if they aren't multiplying.

It quickly becomes an ecosystem. All with an increase need for P. P does not go away. It must be physically exported. We are not lucky enough to have it off gas like the other elements. It accumulates.

An ecosystem is actually the goal. The difference I would point out is that by being within the biomass of the sandbed, it accumulates where no other organism can use it and where there is almost unlimited storage capacity in the form of bacteria. If the sandbed was totally full with bacteria, any further cell division would result in free floaters which carry this excess away to be removed by something eating the bacteria (sponges) and incorporating it into that biomass or it gets removed by the skimmer. The cell remains intact so that phosphate is not available for algae to use it.

What i am getting at is that if there is any increase biomass, then there must also be an in crease in P and N to support that biomass. If the point of a DSB is to convert nitrate to N2, then there must be a thriving biomass in the substrate to accomplish this. All of this biomass was not there when the substrate was installed. How did they get there? What is "fueling" it. All of this points to an increase in nutrients within the substrate. If there wasn't this increase, than the substrate would not increase its ability to accomplish its task of converting nitrates to N2. An entire system is not being supported by a single individual bacterium. It has friends. A whole lot of friends.

Everything in that statement is true.

Unfortunately a lot of those friends also die.

Except this.

If you aren't disturbing the sand bed and there are no critters eating the bacteria, what kills them? If they aren't killed, they are just living in the sand bed and each is reproducing as fast as it accumulates the necessary nutrients to do so. I honestly thing it will take a lot of years before the sand bed has reached the space limit for the bacteria. And unless you are PaulB or one of the lucky few, most tank setups don't last more than 10-20 years. By that time there are so many critters fighting for the same nutrients that the workings of the sand bed bacteria are limited by other things instead of phosphates.

Friendly Regards,

 

[CuzzA]

What rocket said.

 

[Swope2bc]

I also agree! And we'll put too!

 

[Dan_P]

I consider all dead organic material detritus. This includes bacterial mulm, poo, and dead organisms.

Bacteria do not live forever. Like any organism, they do die. The P and N that they contain must go somewhere. What happens with those? If they are utilized by bacteria, then we must count those bacteria as part of the biomass and all of the resources needed to sustain them. It quickly becomes an ecosystem. All with an increase need for P. P does not go away. It must be physically exported. We are not lucky enough to have it off gas like the other elements. It accumulates.

What i am getting at is that if there is any increase biomass, then there must also be an in crease in P and N to support that biomass. If the point of a DSB is to convert nitrate to N2, then there must be a thriving biomass in the substrate to accomplish this. All of this biomass was not there when the substrate was installed. How did they get there? What is "fueling" it. All of this points to an increase in nutrients within the substrate. If there wasn't this increase, than the substrate would not increase its ability to accomplish its task of converting nitrates to N2. An entire system is not being supported by a single individual bacterium. It has friends. A whole lot of friends. Unfortunately a lot of those friends also die.

G~

These are not unreasonable propositions. If true, all aquarium substrates will eventually stop functioning and ruin the water quality in the sytem. So, to keep an eye on my substrate, I have started to measure pore water chemistry. Also, I am trying to come up with additional, affordable methods to measure organic material in the substrate. This should give me a heads up on bad trends down below, which is a hope. My system has silica sand and granite stones in place of live rock. This set up eliminates the complication of having aragonite adsorption as a reason for accumulation. This time next year, I will have a year's worth of data.

 

[Reefin' Dude]

Actually, bacteria theoretically do live forever because when they split, they are two copies of the original. Now, certain individuals will die, but this is mostly due to conditions changing where they live or some other organism killing them.

They do not live forever. Some can live for very long periods of time, but it is not all of them. They can go dormant. If they did live forever, then there would not be any room on the world for any other organism, or there would not be any resources for any other organisms. The bacteria would have utilized them all since life began on Earth.

One can not have an ecosystem without organisms dying. From the Wikipedia page about bacteria.

"The final phase is the death phase where the bacteria run out of nutrients and die."

There is a big difference between bacteria sustaining their current population and bacteria that are growing their population. A bacteria only splits when it has enough materials and energy to do so. They still use oxygen even if they aren't multiplying.

What happens when they do not have enough resources? Where did those initial resources come from to start the bacterial growth in the substrate? What is keeping those initial resources used by the bacteria from accumulating again?

An ecosystem is actually the goal. The difference I would point out is that by being within the biomass of the sandbed, it accumulates where no other organism can use it and where there is almost unlimited storage capacity in the form of bacteria. If the sandbed was totally full with bacteria, any further cell division would result in free floaters which carry this excess away to be removed by something eating the bacteria (sponges) and incorporating it into that biomass or it gets removed by the skimmer. The cell remains intact so that phosphate is not available for algae to use it.

If an ecosystem is a goal, then there must be bacterial death. There must also be an accumulation of resources in order to support the growing biomass of all of the organisms in the substrate. You can not have a growing biomass without a increase in resources going into and out of the organisms.

It doesn't work that way. We all wish it did, but it doesn't. Take any substrate and stir it up. You will find a lot of material in there that was not there when the substrate was put in. Where did it all come from? It is all organic material. If what you said was true, then there would not be any organic material in a substrate at all, and substrates would not be useful for converting nitrates to N2. It would not do anything at all. There would not be any life in it.

Except this.

But bacteria do die. This one fact means that substrates accumulate. There will need to be bacteria eating the dead bacteria to get the resources "locked up" in the dead bacteria back into the ecosystem to sustain it. This all leads to an accumulation of organic material. If there is any organic material, then there is also going to be waste organic material from the organisms. The substrate is going to accumulate material.

If you aren't disturbing the sand bed and there are no critters eating the bacteria, what kills them? If they aren't killed, they are just living in the sand bed and each is reproducing as fast as it accumulates the necessary nutrients to do so. I honestly thing it will take a lot of years before the sand bed has reached the space limit for the bacteria. And unless you are PaulB or one of the lucky few, most tank setups don't last more than 10-20 years. By that time there are so many critters fighting for the same nutrients that the workings of the sand bed bacteria are limited by other things instead of phosphates.

Friendly Regards,

The bacteria die. They will run out of resources. They will get consumed by other organisms.

Now they are accumulating the necessary nutrients to do so? Where is all of the P coming from for them to reproduce? All cels need P. If there is an increase in bacterial biomass, then there must be an increase in P to support that increase. There are a lot of other resources needed for organism growth. Keeping up with N and P are hard enough, but it keeps it reasonable. P is the easiest to grasp for most people because it is the main resource that does not off-gas. It needs to be physically removed from a system.

Paul_b- actually cleans his substrate regularly. I believe he calls them Typhoons. He believes that substrates do accumulate organic material and it needs to be cleaned of it on a regular basis. His regular basis can be years, but he does clean his substrates. That is all i am saying here. If you want to run a DSB, whether remote or otherwise, then clean it or replace it on a regular basis to remove the organic material and restart the bacterial populations.

G~

 

[RocketEngineer]

Lets look at the chemistry of what we are talking about.

Phosphates are used to make ATP which is the main energy transfer mechanism within cells. It is one of the limiting nutrients in biology because without enough of it, the cells can't divide due to a lack of energy.

Nitrogen can also be a limiting nutrient in biology because of how many compounds have a nitrogen atom somewhere within their molecular structure. Proteins, DNA, even ATP. As a reference ATP has 3 phosphorous atoms and 5 nitrogen atoms.

So where does nitrate fit into all this? Nitrates are an electron acceptor used during respiration of carbon compounds in low oxygen environments. The nitrogen in nitrates are used in place of the more energetically favorable oxygen. What happens is that electrons freed during breaking of carbon bonds plus hydrogen combine with oxygen and nitrogen atoms of the nitrate molecule to form N2 and H2O. (See Denitrification).

So while each of these nutrients are being pulled into the sand bed and used by the bacteria in some form, they are not being used at the same rate. Phosphorous is being incorporated into the cellular structure of the bacteria and once inside is continuously recycled within the bacteria as ATP and its precursors. By contrast, nitrogen is a key building block of amino acids and therefore proteins of which there are a significantly higher number of compared to phosphorous.

To look at this this problem another way, I put forward the following questions with respect to the workings of a Bucket DSB:
What is the goal of the Bucket DSB? To remove nitrates from the aquarium.
Why? To cause the system to go from being a phosphate limited system to being a nitrate limited system.
What purpose does that serve? By being a nitrogen limited system, we are able to better combat algae growth within the tank because the algae is fighting the anoxic bacteria for nitrates to which the bacteria are actively removing from the tank.
Why does that work better in a Bucket DSB compared to in the rest of the tank? The conversion of ammonia to nitrate occurs on every surface of the tank. In a Bucket DSB, the bacteria responsible for converting ammonia into nitrate are now in close proximity to the bacteria that are using the nitrates for anoxic respiration. , the nitrates have just as likely a chance of diffusing up out of the top of the sand as it does down to where the bacteria are actively converting it into nitrogen gas.
How is this different from inside the display?In the display, the nitrates released by the bacteria gets released into the water column and therefore is readily accessible to the algae for growth. By contrast, any nitrates that travel lower into the sand bed will be broken down and released into the air and can no longer contribute to biomass growth.

Where does this leave us? The Bucket DSB is designed to gradually reduce the amount of nitrates present in our tanks. It does this using anoxic environments in close proximity to nitrifying bacteria. This close proximity prevents a portion of the nitrates from being released into the water column and instead they are broken into water and nitrogen gas. Given enough time and a sufficiently large concentration of denitrifying bacteria, the tank becomes nitrogen limited and the algae must now compete with the higher life of the tank that are actively capturing the food particles before they are broken down into molucules the algae can use. Without a readily available source of nitrates, the algae die off while the bacteria (using ammonia as their nitrogen source) continue to thrive.

I hope that makes sense. Lots of chemistry involved.

 

[power boat jim]

The science you describe appears solid, however that process will not go on forever in a plastic bucket full of sand. As said before the sand gets so over run with dertritus it ceases to function in the manner it was ment to and becomes a source for nutrients instead of way to process them out. One thing that forms when organic material decomposes in an oxygen poor environment is H2s. There is no getting around its formation when that condition is present.

Keep the sand bed clean and dont alow detritus to compact at lower depths and that is easily avoided. I tried a dsb in hopes it was magic and makes everything bad dissappear, it does not. It clogs up over time and produced what every other pile of oxygen starved organic matter does, it produced hydrogen sulfide.

Im not saying a sand bed cant be beneficial if you maintain it. I just dont see it how something can work forever without help. Entropy seems to prevent that.

 

[CuzzA]

DSB in a bucket for nitrate control

I think the big point here that's getting lost about the bucket deep sand bed is it's remote and can easily be taken off line. So even if it eventually goes south, this could be many many years into the future. Unlike the in tank deep sand bed. So years of worry free low nitrates has a huge advantage IMO over many of the other techniques that require daily to weekly attention or use of consumables that cost money. I look at a product like NOPOX and just smh.