Looking for thoughts on organic carbon dosing and nitrate

[Stigigemla]

I have several customers that tried carbon dosing.
It seems to be differencies in the start depending on what kind of carbon You add.
The fastest way to start seems to be with Red Seas NO3PO4ex = nopox normally a week or less.
Vodka + vinegar 1 or 2 weeks.
Vodka + vinegar + sugar the same
Biopellets 1 or 2 months. Maybe that can be different depending on brand.
Sugar only is just tried a few times but gave a very hard consistent foam so the skimmer overflow. I dont know how fast the tanks started.
I also dont know if we get the same tribes of bacteria with different food but a few of my customers have switched the carbon media and it seems that it works practically seamless.
All this is from functioning aquaria with nitrate about 20 to 60.

A usual problem is in tanks where phosphate reduction medias have been used.
It is hard to convince some customers that they have to dose phosphate to get the nitrate down.

 

[biom]

It is frequently claimed that it takes a long time (sometimes weeks) for organic carbon dosing to reduce nitrate.

Do folks believe that is true, and if it is, why would it be true?

Are most folks just starting to dose too slowly?

Bacterial number increase is sometimes cited as a reason, but why would it take that long?

If bacterial numbers increase is the reason, then where is the organic carbon going in the meantime? Accumulating? Being used somehow in a way that does not consume nitrate? What way is that?

Any thoughts are appreciated.

I think this is true, I am dosing carbon (ethanol/acetic acid) and every time I am starting with a new tank there is always a lag time before nitrates go down. This lag time is different from 4-5 days up to 2-3 weeks. And starting with larger dosses does not help - every time dangerous clouding of water emerges that depletes oxygen level with no significant influence of nitrate level.

My explanation is the heterotroph nitrate-assimilating bacteria (NAB) capable of nitrate assimilation (reducing nitrates to ammonia and then producing amino acids) in aerobic conditions need a little bit more time to scale up than the other more common heterotroph bacteria which are not capable of nitrate assimilation but are also using ethanol/acetic acid as energy source in the tricarboxylic acid cycle (Krebs cycle). And for the needs of protein production they are using ammonia or organic nitrogen sources but not nitrates. That clouding we see soon after overdosing with carbon is probably caused of such strains (like Bacillus).

Nitrate-assimilating bacteria (NAB) are also using carbon as energy source but part of this energy is directed for reducing nitrates to ammonia giving them advance in this competitive environment.

That is why when adding carbon source we are giving advance to NAB over the algae which are also capable of nitrate assimilation but are using photosynthesis as energy source to reduce nitrates down to ammonia.

Good reading of the poorly understood marine heterotrophic bacteria:
Jiang, X., Jiao, N. Nitrate assimilation by marine heterotrophic bacteria. Sci. China Earth Sci. 59, 477–483 (2016). https://doi.org/10.1007/s11430-015-5212-5

 

[biom]

Phosphate removal is another biological process, not related to nitrate reduction. That is why nitrate removal and phosphate removal are often not related and different result can be seen in different tanks after carbon source is added. Phosphate removal is poorly understood but probably Polyphosphate-accumulating organisms (PAO) are involved - they can consume acetate (vinegar) under anaerobic conditions and store the energy store by accumulating polyphosphate. This process is used in wastewater treatment. The main difference from the other bacteria here is that the phosphates in PAO are not used for needs of growth they are stored in bigger amounts as an energy source.

Is this process good for our reef tanks? I don’t know, it could be – if this PAO bacteria are removed by the skimmer. But if not, which is quite possible – these bacteria are anaerobic (they don’t need oxygen)– so they would live deep in the live rock or in the deep sandbed, which means after they die large quantities of accumulated phosphates will be trapped in the life rock and will be slowly released back in the water or (worse) will be used by nuisance algae on the rock. This is actually happening with old tanks – so called old tank syndrome.

 

[hmfaysal]

I have a story to share. I have always run dirtier tanks than usual, hence I always needed some sort of heavy export method from the beginning. I tried Aquaforest NP Minus for 2 months, which is some sort of organic carbon polymer, I tried half dose for a week, full dose for a week, almost no results, tried half a bottle because why not, it worked maybe, but I cannot prove it quantitively. I tried Red Sea Nopox, the nutrients would start coming downhill like avalanche the next day. No cyano, nothing. I supplemented miracle mud with it, so the phosphates and nitrates leaching from the mud complements the reduction rate.

The weirdest thing happened when I tried DIY nopox with vodka+vinegar. Works, but doesn't work as efficiently Red Sea Nopox. I tried sugar+vinegar (164g sugar in enough rodi water to make 430ml solution with 570ml 5% acetic acid), that fueled all sorts of growth, cyano in the refugium in particular. The cyano did not bother me much, in fact, the nutrient export was the highest with cyano. I used to grab a fist sized blob every other night from the fuge. With cyano, the amphipod population exploded. I have no idea why or how. And only with Sugar+Vinegar the phosphate reduction was noticable with subsequent testing, around 0.05ppm reduction per week. Again don't know why or how, but it only happens when there is blobs of cyano. Picture here:

What is this snotty looking thing growing in my refugium?

Pulled out a couple of handful of these snotty looking stuff today, looks kinda purple brown, can someone kindly id? Thanks

www.reef2reef.com

But nothing works wonders like Nopox, I know it has methanol added to it, some say the methanol is there to make the solution methylated so that RedSea can ship and sell in different jurisdictions with tighter alcohol laws. But to me, that small bit of methanol is the only thing that makes Nopox different. It acts differently, works differently. SoB even worked slowly, but surely when phosphates bottomed out, using phosphates as it was produced. With nopox the filter feeders specially the growth of sponges skyrocket.

I use organic carbon dosing to fuel different growths, If I need sponges to grow, I dose RedSea Nopox. If I need to reduce nitrates I dose diy Vinegar+sugar, also has the side effect of boosting my amphipod population. For Phosphate control, I use GFO, and recently use LaCl and killed one of my favorite fishes, a blue spot sleeper goby. That's a story for another day. And I would like to iterate, Sugar+Vinegar is dangerous, if tank is not fully established, then there will be cyano, and if the cyano ends up in the DT, oh boy. DIY Nopox is good, but not fast acting as the Red Sea Nopox. I again concur, me belief is, its the tiny bit of methanol added to the RedSea Nopox which makes it so much fast acting and potent. I need to figure out a way to test my theory though. Can somebody help?

 

[SDchris]

My explanation is the heterotroph nitrate-assimilating bacteria (NAB) capable of nitrate assimilation (reducing nitrates to ammonia and then producing amino acids) in aerobic conditions

If organic carbon simply increases respiration (sediment) that would cause a low O2 environment and N to exist as ammonia and never ending up as nitrate. Such conditions would also support the formation of benthic cyano blooms, which we know also occur often when starting carbon dosing.

 

[Dan_P]

Started with carbon dosing on my 20g system after a month of nitrates in the 20s on my heavily stocked system. Over the course of a week I ramped up quickly to 8ml vinegar with minimal movement. Decided to try my hand at some diy NoPox (50% 5% vinegar/50% Tito’s) starting at 3ml and saw a near immediate response. 2.5 weeks later I’m averaging 10 ppm (average daily decrease of 0.75 ppm). Never had any clouding, just a daily dusting of I’m assuming easily removable bacteria on the glass.

Above makes me wonder if certain systems respond differently to vinegar vs vodka, possibly accounting for how quickly nitrate lowers with dosing.

1 mL of vinegar per gallon is roughly where you needed to reach. If you are using vodka that would work out to be 1/8 mL per gallon. For a 20 gallon system, that works out to 20 mL vinegar or 2.5 mL vodka

In your first attempt the vinegar dose was 40% of the effective dose. For the NOPOX dose, ~75%% of the effective dose was achieved. I conclude the NOPOX worked because the dose was higher and the vinegar did not work because the dose was too low.

 

[chipchipbro]

I did also start dosing Carbon to bring down my NO3 (it was 40)
I dosed and dosed and dosed and nothing happened.. I did only get that slime build up on my powerheads and everywhere.

Then I noticed that my PO4 was below 0.05 and I started to dose PO4....

After dosing po4 and keeping it around 0.10 it started to work.. NO3 did come down.

The only thing I hate it the slime build up from bacteria.....

 

[Randy Holmes-Farley]

Should we expect a different outcome depending on the N source? fish vs sediment.

If you are talking about the source of nitrate and whether the source matters for the ability of any process to use that nitrate, the answer is no. The nitrate does not retain any property that depends on its original source.

 

[Randy Holmes-Farley]

I have a story to share. I have always run dirtier tanks than usual, hence I always needed some sort of heavy export method from the beginning. I tried Aquaforest NP Minus for 2 months, which is some sort of organic carbon polymer, I tried half dose for a week, full dose for a week, almost no results, tried half a bottle because why not, it worked maybe, but I cannot prove it quantitively. I tried Red Sea Nopox, the nutrients would start coming downhill like avalanche the next day. No cyano, nothing. I supplemented miracle mud with it, so the phosphates and nitrates leaching from the mud complements the reduction rate.

The weirdest thing happened when I tried DIY nopox with vodka+vinegar. Works, but doesn't work as efficiently Red Sea Nopox. I tried sugar+vinegar (164g sugar in enough rodi water to make 430ml solution with 570ml 5% acetic acid), that fueled all sorts of growth, cyano in the refugium in particular. The cyano did not bother me much, in fact, the nutrient export was the highest with cyano. I used to grab a fist sized blob every other night from the fuge. With cyano, the amphipod population exploded. I have no idea why or how. And only with Sugar+Vinegar the phosphate reduction was noticable with subsequent testing, around 0.05ppm reduction per week. Again don't know why or how, but it only happens when there is blobs of cyano. Picture here:

What is this snotty looking thing growing in my refugium?

Pulled out a couple of handful of these snotty looking stuff today, looks kinda purple brown, can someone kindly id? Thanks

www.reef2reef.com

But nothing works wonders like Nopox, I know it has methanol added to it, some say the methanol is there to make the solution methylated so that RedSea can ship and sell in different jurisdictions with tighter alcohol laws. But to me, that small bit of methanol is the only thing that makes Nopox different. It acts differently, works differently. SoB even worked slowly, but surely when phosphates bottomed out, using phosphates as it was produced. With nopox the filter feeders specially the growth of sponges skyrocket.

I use organic carbon dosing to fuel different growths, If I need sponges to grow, I dose RedSea Nopox. If I need to reduce nitrates I dose diy Vinegar+sugar, also has the side effect of boosting my amphipod population. For Phosphate control, I use GFO, and recently use LaCl and killed one of my favorite fishes, a blue spot sleeper goby. That's a story for another day. And I would like to iterate, Sugar+Vinegar is dangerous, if tank is not fully established, then there will be cyano, and if the cyano ends up in the DT, oh boy. DIY Nopox is good, but not fast acting as the Red Sea Nopox. I again concur, me belief is, its the tiny bit of methanol added to the RedSea Nopox which makes it so much fast acting and potent. I need to figure out a way to test my theory though. Can somebody help?

Just an fyi, NOPOX also contains a small amount of isopropanol, so methanol is not the only difference from some other organic dosing schemes.

 

[cpschult]

It is frequently claimed that it takes a long time (sometimes weeks) for organic carbon dosing to reduce nitrate.

Do folks believe that is true, and if it is, why would it be true?

Are most folks just starting to dose too slowly?

Bacterial number increase is sometimes cited as a reason, but why would it take that long?

If bacterial numbers increase is the reason, then where is the organic carbon going in the meantime? Accumulating? Being used somehow in a way that does not consume nitrate? What way is that?

Any thoughts are appreciated.

When I overdosed my tank with carbon I ended up with a cyano outbreak. I'm assuming I was feeding the "wrong" bacteria.

 

[biom]

Just an fyi, NOPOX also contains a small amount of isopropanol, so methanol is not the only difference from some other organic dosing schemes.

Yes, but I dont think methanol and isopropanol are there on reason related to bacteria growth. They are in very small concentration and they are common ingredients of denatured alcohol - methanol is added because it is poisonous (for humans) and isopropanol because has very strong odor - actually isopropanol is one of the the reasons of the specific smell of NoPox.
I've tested several versions of DIY Nopox - one with all the same ingredients like the original, one with only pure ethanol and acetic acid, one with ethanol and sodium acetate (to avoid pH lowering and acetic smell) and one with methanol (in high concentration like ethanol in the original) and acetic acid. Dosed each for couple of months with the same concentration and did not notice any significant differences - they were all keeping my nitrates low. Only I've stopped dosing methanol/acetate after one month because nothing wrong happened but strange formaldehyde smell appear near the display and I got nervous about possible dangerous (for humans) by-products of methanol degradation.

That is why I am using DIY from pure ethanol and acetic acid, but quite often I am replacing acetic acid with sodium acetate to avoid the acetic smell I dont like.

 

[Randy Holmes-Farley]

Yes, but I dont think methanol and isopropanol are there on reason related to bacteria growth. They are in very small concentration and they are common ingredients of denatured alcohol - methanol is added because it is poisonous (for humans) and isopropanol because has very strong odor - actually isopropanol is one of the the reasons of the specific smell of NoPox.
I've tested several versions of DIY Nopox - one with all the same ingredients like the original, one with only pure ethanol and acetic acid, one with ethanol and sodium acetate (to avoid pH lowering and acetic smell) and one with methanol (in high concentration like ethanol in the original) and acetic acid. Dosed each for couple of months with the same concentration and did not notice any significant differences - they were all keeping my nitrates low. Only I've stopped dosing methanol/acetate after one month because nothing wrong happened but strange formaldehyde smell appear near the display and I got nervous about possible dangerous (for humans) by-products of methanol degradation.

That has been my assumption as well.

 

[hmfaysal]

Just an fyi, NOPOX also contains a small amount of isopropanol, so methanol is not the only difference from some other organic dosing schemes.

Ah, I did not know that, and I can't really think of any way how it may increase the effectiveness of the concoction.

 

[hmfaysal]

When I overdosed my tank with carbon I ended up with a cyano outbreak. I'm assuming I was feeding the "wrong" bacteria.

Oh boy, I was harvesting thick blobs of cyano colonies from my refugium. The size was exactly the size of my oversized rubber gloves (They break when harvesting, so whatever I can scoop on my gloves) of jelly consistency. I used to throw away two glove palm sized cyano jellies every couple of days. The growth fueled as I ramped up both the Sugar-Vinegar mix (upto 60ml per day in 120g total volume) and the lighting in the refugium, a 50 watt purple grow light with 600 par on the surface. The chaeto grew with visible bubbles, cyano overtook, if I didn't remove the cyano, the surface would be covered by cyano jellies in a matter of days, no matter the flow.

 

[Court_Appointed_Hypeman]

Oh boy, I was harvesting thick blobs of cyano colonies from my refugium. The size was exactly the size of my oversized rubber gloves (They break when harvesting, so whatever I can scoop on my gloves) of jelly consistency. I used to throw away two glove palm sized cyano jellies every couple of days. The growth fueled as I ramped up both the Sugar-Vinegar mix (upto 60ml per day in 120g total volume) and the lighting in the refugium, a 50 watt purple grow light with 600 par on the surface. The chaeto grew with visible bubbles, cyano overtook, if I didn't remove the cyano, the surface would be covered by cyano jellies in a matter of days, no matter the flow.

I wonder if this is why my pod population has been skyrocketing since about 2 weeks into carbon dosing. I don't see any cyano at all, and I started with the max dose. I also noticed my GHA (not 100% its gha, its pretty thick strands, more like a turfy looking java moss) is disappearing, so idk if bacteria is just out competing the algae, or the boom in pods is wiping it out faster. The seem to suck the chlorophyll out of the strands and the clear remained breaks off. I've had this "gha" for about 2 months and it hit a point where a couple rocks were covered, but stopped spreading about 2 weeks prior to carbon dosing, after starting the carbon dosing it stipped gaining length.

Edit: the assumption I am making is that I am getting cyano, but the pods are consuming it before it is visible, giving them a nutritional boost.

 

[hmfaysal]

I wonder if this is why my pod population has been skyrocketing since about 2 weeks into carbon dosing. I don't see any cyano at all, and I started with the max dose. I also noticed my GHA (not 100% its gha, its pretty thick strands, more like a turfy looking java moss) is disappearing, so idk if bacteria is just out competing the algae, or the boom in pods is wiping it out faster. The seem to suck the chlorophyll out of the strands and the clear remained breaks off. I've had this "gha" for about 2 months and it hit a point where a couple rocks were covered, but stopped spreading about 2 weeks prior to carbon dosing, after starting the carbon dosing it stipped gaining length.

Edit: the assumption I am making is that I am getting cyano, but the pods are consuming it before it is visible, giving them a nutritional boost.

My bet would be on cyano, and getting gobbled up by amphipods. The GHA becomes pale and weak, in my brief experience, cyano has a tendency to outcompete any living organism, apart from pods.

So does that make pods the strongest? But my mandarin couple hunt these down all day long. Does that make the mandarin couple the strongest? But they stay behind the rocks at the back of my tank. I am confused.

 

[SDchris]

If you are talking about the source of nitrate and whether the source matters for the ability of any process to use that nitrate, the answer is no. The nitrate does not retain any property that depends on its original source.

I was thinking more water column vs pore water derived N. I'll rephrase it. Would carbon dosing behave the same way in a completely bare tank using a wet/dry bioball filter vs a tank using sand/rock? Both having equal fish loads.
If sediments pore water was the main source of nitrate, increasing the sediment BOD with carbon dosing, going from aerobic to anaerobic, resulting in a shift from nitrate to ammonium release, should be a different path and time frame to the bioball scenario.

 

[ScottB]

No need to look for a second shooter. Starting too low, taking too long to ramp up the dose, and never reaching a high enough dose to support strong bacteria growth. Also, I think many aquarist quit before the dose is high enough.

I think the problem stems from the popular dosing chart that incorrectly scales the dosing. I pointed this out some time ago and I think you might have published a corrected version.

This. We all start off using that chart and take many weeks to get to an effective dose.

 

[Randy Holmes-Farley]

I was thinking more water column vs pore water derived N. I'll rephrase it. Would carbon dosing behave the same way in a completely bare tank using a wet/dry bioball filter vs a tank using sand/rock? Both having equal fish loads.
If sediments pore water was the main source of nitrate, increasing the sediment BOD with carbon dosing, going from aerobic to anaerobic, resulting in a shift from nitrate to ammonium release, should be a different path and time frame to the bioball scenario.

By definition, nitrate in the water column will be impacted equally no matter where it came from.

It is true that organic carbon will have different molecular mechanisms for being consumed in different environments that will impact N and P in those different environments differently.

 

[Smarkow]

Bacterial number increase is sometimes cited as a reason, but why would it take that long?

If bacterial numbers increase is the reason, then where is the organic carbon going in the meantime? Accumulating? Being used somehow in a way that does not consume nitrate? What way is that?

There are two (IMO) additional factors that I would consider… (and prob many more)

First, what is the source of organic carbon? Alcohol, acetic acid, citric acid?
Amino acids (are we sure we know what these are doing in our tanks?) Are those amino acids phosphorylated?
How about “marine snow” type products?

Second, what is the starting microbiome? Frankly I remain unconvinced that we are even certain which bacteria are using the carbon sources we specifically add to carbon dose. Does carbon dosing change the microbiome? (Almost certainly) If it does change it, how and in what ways?

I think we are reasonably far from having answers, but rather at the black box stage of the diagram. But good topic for discussion