Poor Man's Nutrients Control - Donovan's Nitrate Destroyer

[SomeHappyFish]

I haven't read the whole things but how effective is this setup ? Is it hard to keep stable?

What have we learn from it? What to use and what not

 

[piranhaman00]

Years ago I purchased one of something just like this, not sure they are still on the market or not. But I had the same issue with the supplied pump. I used a dosing pump to fix the issue with mine. Worked like a charm after wards. Just need to make sure its continuous duty and adjustable.

Yes I looked into using a dosing pump but too expensive for continuous duty haha

I
I used a t split from the return pump.

I just rigged up some plumbing to use my return drain to feed it. I have high hopes!

I haven't read the whole things but how effective is this setup ? Is it hard to keep stable?

What have we learn from it? What to use and what not

It works very well but in my case too well and starts producing H2S, I’m having trouble making a consistent supply of water.

 

[twentyleagues]

Yes I looked into using a dosing pump but too expensive for continuous duty haha


I just rigged up some plumbing to use my return drain to feed it. I have high hopes!


It works very well but in my case too well and starts producing H2S, I’m having trouble making a consistent supply of water.

The only problem with the use of the drain is detritus.

 

[piranhaman00]

The only problem with the use of the drain is detritus.

Potentially clotting issues?

 

[blazn]

Yes I looked into using a dosing pump but too expensive for continuous duty haha


I just rigged up some plumbing to use my return drain to feed it. I have high hopes!


It works very well but in my case too well and starts producing H2S, I’m having trouble making a consistent supply of water.

Like Levinson, I also just T-split from an existing pump, in my case, the pump that feeds my GFO/AC dual reactor, using a valve on the T. Initially the valve needed a lot of adjustment, but over time, valve adjustments are infrequent. I have never run into an issue with my DND clogging. I do use airline tubing for my output line and I replace it with new tubing a couple times a year.

 

[SPS clown]

It sounds like you've got your DND setup correctly, so I expect you only need some minor tweaking and a bit of time. Adding another bacteria source (Dr. Tims) was probably a good move. I only dose vodka & don't have experience with vsv, but when I was ramping up my initial phase of my DND, I maxed at 20ml/day of vodka. My maintenance dose (after my DND was fully functional) is 4-5ml/day of vodka. So, I would think that you may want to ramp up your vsv dosage during your initial phase. Whatever you do, be patient, you'll get there and it's worth it!

so its been 10 more days - dosed the bottle of tims. I have observed that my flow rate has decreased a couple of times so i have increased the flow. Im also getting more back pressure into the intake that if i turn it all the way up it will come out the top of the intake/dosing port so something is def happening in there. the nitrates on the effluent may be slightly lower today.. they have been testing darkest on the salifert test this whole time. today they might be one shade lower.. Im out of tests on my hanna checker so not an exact number. pluse that would get kinda expensive during this phase. Dosing 25ml vodka per day and flow rate is probably 3ml/second, maybe slightly higher.

Ill just let it keep going - day 45 though. thought it woulda kicked in a little by now.

 

[mikst]

I read the build page on this, I can't read another 71 pages tho, hah. I have a couple questions, isn't this basically like producing a cryptic sump? You're creating a very slow flow, dark environment, and with the carbon dosing you're providing fuel to build heterotrophic bacteria from nitrate and phosphate? Those are in turn consumed by filter feeders in the cryptic environment?

I saw mention of catching the effluent in a coffee filter like a filter sock, isn't that similar to removing skimate from a skimmer when carbon dosing where you're just removing the nitrates that are wrapped up in bacteria?

What evidence is there that it is truly an anaerobic environment where true denitrification can take place? As opposed to simply an oxygen depleted environment wherein there is assimilatory denitrification (nitrates are absorbed into living creatures as they grow)?

 

[Levinson]

I read the build page on this, I can't read another 71 pages tho, hah. I have a couple questions, isn't this basically like producing a cryptic sump? You're creating a very slow flow, dark environment, and with the carbon dosing you're providing fuel to build heterotrophic bacteria from nitrate and phosphate? Those are in turn consumed by filter feeders in the cryptic environment?

I saw mention of catching the effluent in a coffee filter like a filter sock, isn't that similar to removing skimate from a skimmer when carbon dosing where you're just removing the nitrates that are wrapped up in bacteria?

What evidence is there that it is truly an anaerobic environment where true denitrification can take place? As opposed to simply an oxygen depleted environment wherein there is assimilatory denitrification (nitrates are absorbed into living creatures as they grow)?

I think one of the differences between this and a cryptic sump is more controllability (flow rate, carbon dosing into a sealed chamber etc). Also, I think there is much less gas exchange(oxygen), if any, within the DND where a cryptic sump would still have the water surface exposed to the air outside. I think a cryptic sump may include some anaerobic zones but they generally serve a different purpose like growing cryptic organisms like sponges or tubeworms which still need some oxygen to live.
I have not seen this in my case but there have been videos or pictures posted on this thread of bubbles exiting the outlet tube which is suspected to be the by-product of the denitrification process by anaerobic bacteria. And there have been cases where sulfur smell had been detected which also could indicate the formation of an anaerobic zone inside.
The carbon being dosed into a sealed chamber would, in theory, deplete the dissolved oxygen inside of DND rapidly and most of the carbon sources dosed would likely be used up before it could exit the DND (this would depend on the amount dosed and flowrate of course), reducing the chances of the carbon reaching places around the tank promoting the unwanted growth of different lifeforms such as cyanos.
Well, that is my thoughts and understanding of the DND but I don't feel confident enough to be sure.

 

[mikst]

I think one of the differences between this and a cryptic sump is more controllability (flow rate, carbon dosing into a sealed chamber etc). Also, I think there is much less gas exchange(oxygen), if any, within the DND where a cryptic sump would still have the water surface exposed to the air outside. I think a cryptic sump may include some anaerobic zones but they generally serve a different purpose like growing cryptic organisms like sponges or tubeworms which still need some oxygen to live.
I have not seen this in my case but there have been videos or pictures posted on this thread of bubbles exiting the outlet tube which is suspected to be the by-product of the denitrification process by anaerobic bacteria. And there have been cases where sulfur smell had been detected which also could indicate the formation of an anaerobic zone inside.
The carbon being dosed into a sealed chamber would, in theory, deplete the dissolved oxygen inside of DND rapidly and most of the carbon sources dosed would likely be used up before it could exit the DND (this would depend on the amount dosed and flowrate of course), reducing the chances of the carbon reaching places around the tank promoting the unwanted growth of different lifeforms such as cyanos.
Well, that is my thoughts and understanding of the DND but I don't feel confident enough to be sure.

that's a great point on the bacterial growth depleting oxygen! I bet that's a huge driving factor. With the first chamber having a vent hole at the top, that seems like an introduction point for air exchange.

I also am interested in why the complication of two chambers. Why not run it like a canister filter, plumbing the inlet to the bottom and letting the flow to up thru the media and overflow out the top? Or reverse of that,inlet dumps onto top of media in a downflow, but the bottom of the tube has a blank space/gap that is plumbed internally with the outlet overflowing out of the container.

 

[Levinson]

that's a great point on the bacterial growth depleting oxygen! I bet that's a huge driving factor. With the first chamber having a vent hole at the top, that seems like an introduction point for air exchange.

I also am interested in why the complication of two chambers. Why not run it like a canister filter, plumbing the inlet to the bottom and letting the flow to up thru the media and overflow out the top? Or reverse of that,inlet dumps onto top of media in a downflow, but the bottom of the tube has a blank space/gap that is plumbed internally with the outlet overflowing out of the container.

The hole for carbon dosing has a valve on it so it is normally closed and only open when dosing carbon. The inlet and the outlet holes are normally filled with inflowing and outflowing water so it is also not in contact with the atmosphere, limiting contact with oxygen except for the dissolved oxygen in the water going into the DND which is not much due to the slow flow rate. The inside of the DND is kind of semi-sealed.
I think you could also have it in different shapes as long as there is enough space for it to work and the flow rate going into the DND is slow enough. A more typical reactor/canister design could also work but I think the U shape makes a lot of sense. It will have media with the surface area from the start to the end. It is easier to DIY too.
I'm sure you are already aware of this but if the DND does not get enough nitrates input or the tank bottoms out on it, you could end up with sulfate which won't be good so beware.

 

[deome]

What evidence is there that it is truly an anaerobic environment where true denitrification can take place? As opposed to simply an oxygen depleted environment wherein there is assimilatory denitrification (nitrates are absorbed into living creatures as they grow)?

I'm an engineer, not a biologist. Only evidence I need to see is effluent with significantly reduced nitrates. It could be powered by goblins or demons for all I care, as long as it does the job without too much downside.

I'm on day 2 for my DND; I found this thread a few weeks ago and just built my version (4" pipe 18" high, 1.5" bioballs all through), will be testing effluent weekly once I order more nitrate test materials.

Question for everyone: any idea why I can't find the slightest mention of this supposed nitrate destroyer on any major Youtube reefing channel? I find this very curious, and the answer has got to be more than "well those channels want to sell you a biopellet reactor instead."

 

[Levinson]

I have modified my DND and added a small circulation pump and fluidized plastic media (like K1) inside close to the exit hole. The pump faces upwards to tumble the plastic media.
I have thought of the idea while learning about the EBPR (enhanced biological phosphate removal) system in wastewater treatment. The EBPR system uses bacteria and carbon to remove phosphate from wastewater and is used for freshwater treatment but I have read it can be done in saltwater as well (but I have not seen any examples of it being used in saltwater environment).
The idea of EBPR system is, that the PAOs (phosphate-accumulating organisms/bacteria) can bind phosphate in their cell when they are in an environment alternating between anaerobic and aerobic zones and when organic carbon is available for them in anaerobic conditions. From what I gather (which might not be 100% correct) when there is carbon available for the PAO bacteria to consume in an anaerobic condition, the PAOs will release the phosphate in themselves into the water while taking in the carbon (so the phosphate level in the water would actually rise) but when they are moved to an aerobic environment afterwards, they would use the energy stored from carbon to take in and bind more phosphate than they have released before from the surrounding water in their cell, ultimately lowering the total phosphate in the water.
I thought the conditions for EBPR systems are quite similar to the DND. The DND also has the water going from anaerobic (inside DND) to aerobic (outside DND) conditions. But for EBPR to work, the PAOs need to be moved out of the anaerobic zone which means they need to be free-floating and be carried by the water which is difficult with such little flow/water movement going into the DND. So I added the fluidized plastic media and a small circulation pump inside hoping the tumbling action and the flow would suspend the PAOs and they would be carried outside. I thought the anaerobic zone would be safe from the introduction of oxygen even with the flow since the amount of the water going into the DND is very small and the flow inside is diffused by all the media inside.
This is just all in my head and I am aware it is very unlikely to work.
I have no way of knowing if this marine PAOs (bacteria) are in my tank or if they can even be obtained. If anything, my established tank is even less likely to have any PAOs since they would have likely been out-competed by the others already (more established tanks tend to have less biodiversity).
Also, it is very difficult to know or test for it even if it did work.
I don't expect much from it and I just did it because it was easy to do. Just drill a hole on the top lid, cut the 3w USB pump wire, run the wire through the hole, connect back the wire, seal the hole with silicone, fill the top exit part of DND with floadized plastic media and run it like a fluidized filter.
Who knows, I might learn something from this somehow.

 

[SPS clown]

so its been 10 more days - dosed the bottle of tims. I have observed that my flow rate has decreased a couple of times so i have increased the flow. Im also getting more back pressure into the intake that if i turn it all the way up it will come out the top of the intake/dosing port so something is def happening in there. the nitrates on the effluent may be slightly lower today.. they have been testing darkest on the salifert test this whole time. today they might be one shade lower.. Im out of tests on my hanna checker so not an exact number. pluse that would get kinda expensive during this phase. Dosing 25ml vodka per day and flow rate is probably 3ml/second, maybe slightly higher.

Ill just let it keep going - day 45 though. thought it woulda kicked in a little by now.

Alright i'm right around the 60 day mark... prior to carbon im testing at the darkest salifert (100PPM)... 30 minutes after dosing VSV 3 days ago my effluent tested at 25ppm and i had some hope but now today its back up to 50PPM. Im dosing 30 ml spread across 6 doses, so every 4 hours

Should i stay the course or open it up and see if somethings wrong? not really sure what it could be though. I could have put in some denser layers but i avoided that on purpose. maybe the water on the upward side is moving through it too quickly?

 

[blazn]

Alright i'm right around the 60 day mark... prior to carbon im testing at the darkest salifert (100PPM)... 30 minutes after dosing VSV 3 days ago my effluent tested at 25ppm and i had some hope but now today its back up to 50PPM. Im dosing 30 ml spread across 6 doses, so every 4 hours

Should i stay the course or open it up and see if somethings wrong? not really sure what it could be though. I could have put in some denser layers but i avoided that on purpose. maybe the water on the upward side is moving through it too quickly?

First off, if you care enough about NO3 to build a DND, I highly recommend that you invest in a Hanna checker for NO3 (as well as PO4), so you have a more precise measurement.

Make sure that you are dosing enough VSV. I only have used vodka, but I'm aware that vinegar is to be dosed at 8-9 times the volume of vodka, so I'd expect that VSV would have a dosage somewhere in between. On my 120gal system, during the initial 'break in' period of my DND, I maxed at 20ml of vodka/day until my DT N03 level reduced to the range I desired.

You also do want to reduce the flow as much as is practical to provide more 'soak' time.

So, you may try increasing VSV dosage and/or reducing flow. Keep it up though, it definitely is worth it and once you get it 'dialed in', it's super easy to maintain.

 

[blazn]

I have modified my DND and added a small circulation pump and fluidized plastic media (like K1) inside close to the exit hole. The pump faces upwards to tumble the plastic media.
I have thought of the idea while learning about the EBPR (enhanced biological phosphate removal) system in wastewater treatment. The EBPR system uses bacteria and carbon to remove phosphate from wastewater and is used for freshwater treatment but I have read it can be done in saltwater as well (but I have not seen any examples of it being used in saltwater environment).
The idea of EBPR system is, that the PAOs (phosphate-accumulating organisms/bacteria) can bind phosphate in their cell when they are in an environment alternating between anaerobic and aerobic zones and when organic carbon is available for them in anaerobic conditions. From what I gather (which might not be 100% correct) when there is carbon available for the PAO bacteria to consume in an anaerobic condition, the PAOs will release the phosphate in themselves into the water while taking in the carbon (so the phosphate level in the water would actually rise) but when they are moved to an aerobic environment afterwards, they would use the energy stored from carbon to take in and bind more phosphate than they have released before from the surrounding water in their cell, ultimately lowering the total phosphate in the water.
I thought the conditions for EBPR systems are quite similar to the DND. The DND also has the water going from anaerobic (inside DND) to aerobic (outside DND) conditions. But for EBPR to work, the PAOs need to be moved out of the anaerobic zone which means they need to be free-floating and be carried by the water which is difficult with such little flow/water movement going into the DND. So I added the fluidized plastic media and a small circulation pump inside hoping the tumbling action and the flow would suspend the PAOs and they would be carried outside. I thought the anaerobic zone would be safe from the introduction of oxygen even with the flow since the amount of the water going into the DND is very small and the flow inside is diffused by all the media inside.
This is just all in my head and I am aware it is very unlikely to work.
I have no way of knowing if this marine PAOs (bacteria) are in my tank or if they can even be obtained. If anything, my established tank is even less likely to have any PAOs since they would have likely been out-competed by the others already (more established tanks tend to have less biodiversity).
Also, it is very difficult to know or test for it even if it did work.
I don't expect much from it and I just did it because it was easy to do. Just drill a hole on the top lid, cut the 3w USB pump wire, run the wire through the hole, connect back the wire, seal the hole with silicone, fill the top exit part of DND with floadized plastic media and run it like a fluidized filter.
Who knows, I might learn something from this somehow.

Definitely an interesting concept. Please keep us posted as to your results!

 

[blazn]

I'm an engineer, not a biologist. Only evidence I need to see is effluent with significantly reduced nitrates. It could be powered by goblins or demons for all I care, as long as it does the job without too much downside.

I'm on day 2 for my DND; I found this thread a few weeks ago and just built my version (4" pipe 18" high, 1.5" bioballs all through), will be testing effluent weekly once I order more nitrate test materials.

Question for everyone: any idea why I can't find the slightest mention of this supposed nitrate destroyer on any major Youtube reefing channel? I find this very curious, and the answer has got to be more than "well those channels want to sell you a biopellet reactor instead."

I agree in that the method behind the NO3 reduction is of zero concern to me (goblins anyone?). My only concern is that it definitely does work.

I never looked for any videos on a DND build, only had this thread to go by. I would guess that there may not be any videos available because those of us who built a DND just posted their build & results here, and speaking for myself, I have no desire to create videos.

 

[SPS clown]

First off, if you care enough about NO3 to build a DND, I highly recommend that you invest in a Hanna checker for NO3 (as well as PO4), so you have a more precise measurement.

Make sure that you are dosing enough VSV. I only have used vodka, but I'm aware that vinegar is to be dosed at 8-9 times the volume of vodka, so I'd expect that VSV would have a dosage somewhere in between. On my 120gal system, during the initial 'break in' period of my DND, I maxed at 20ml of vodka/day until my DT N03 level reduced to the range I desired.

You also do want to reduce the flow as much as is practical to provide more 'soak' time.

So, you may try increasing VSV dosage and/or reducing flow. Keep it up though, it definitely is worth it and once you get it 'dialed in', it's super easy to maintain.

Thanks - I actually have a hanna just am out of packets. my carbon source is probably 95% vodka i just had a little bit of phos-x left so i dumped it in the vodka bottle.

I will apply those changes and see how things go. Thanks again.

 

[SPS clown]

Thanks - I actually have a hanna just am out of packets. my carbon source is probably 95% vodka i just had a little bit of phos-x left so i dumped it in the vodka bottle.

I will apply those changes and see how things go. Thanks again.

I got my hanna packets.
Pre carbon dose test from the effluent : 51.6
30 minutes later 60.8
30 additional minutes: 60.7

So ... it obv went up after dosing

My flow is currently very low, basically a slow drip

Im currently dosing 4ml, every 2 hours. It was a very slow ramp up to that over the last 9 weeks

 

[blazn]

I got my hanna packets.
Pre carbon dose test from the effluent : 51.6
30 minutes later 60.8
30 additional minutes: 60.7

So ... it obv went up after dosing

My flow is currently very low, basically a slow drip

Im currently dosing 4ml, every 2 hours. It was a very slow ramp up to that over the last 9 weeks

If it was me, I'd keep increasing my carbon source dose until you got the result you're looking for, at which point you'd then drop it down to a maintenance level.

 

[piranhaman00]

Years ago I purchased one of something just like this, not sure they are still on the market or not. But I had the same issue with the supplied pump. I used a dosing pump to fix the issue with mine. Worked like a charm after wards. Just need to make sure its continuous duty and adjustable.

What dosing pump do you use?