When and why did dosing nitrates start?

[MnFish1]

I'll answer both your questions here...

First is that aerobic denitrification is definitely happening but to be sure not in a way a hobbyist can test for.

Second the science that is out there can explain almost everything that happens anecdotally in your tank when looking at the big picture. This thread is talking about the nitrogen cycle. A well established scientific fact. Add nitrates and things improve, well you know the tank was nitrogen starved.

However as we move forward articles like this suggest to me that ammonia is a better way forward

https://www.nature.com/articles/s41598-020-68916-0
Now this is in relation to thermal tolerance but I will argue that it does give us insight into stress tolerance in relation to nitrogen forms.

I dont understand - so what you're really saying is 'aerobic denitrification doesnt occur to a significant degree'? It wasnt clear (that was the only reason I could think of that the 'hobbyist couldnt test for it).

Second - I agree - there are various articles that suggest certain things - but - one point I tried to make - is that even successful tanks vary considerably - on their bacterial content - and diversity - so maybe a lab study on metabolism is not as applicable as you think it might be?

 

[taricha]

On my old tank I had auto feeders going 6-8x a day plus feeding frozen and nori. I think it’s important we keep in mind we can’t paint every system with the experiences of a few people, different systems can be drastically different on live stock and how they process nutrients.

Thanks! That's the sort of info that I find interesting as it is harder to explain. NO3 ought to be the least desirable N for in a system that gets food inputs like you had. And yet, your corals clearly had a ravenous appetite, and enjoyed the NO3 supplement.
Given that you were trying to max out calcification for a grow out contest, I'm guessing your PO4 was as low as you could get it too?

I love your [Lasse] sayings:)

was thinking that myself. half the time I think they are real swedish expressions, and I think the other half @Lasse makes up for entertainment.

I am not a scientist, but did not the second paper show multiple studies where in dinoflagellates were NH4 inhibited in certain circumstances and is that not relevant?

unfortunately the math on that is that dino inhibition happens around ~1ppm ammonia, so it's only relevant as to why attempts to grow them in bottles and small cultures often flop.
In our tanks the ammonia levels are far lower, and dinos take ammonia just fine in those doses.

 

[flampton]

I dont understand - so what you're really saying is 'aerobic denitrification doesnt occur to a significant degree'? It wasnt clear (that was the only reason I could think of that the 'hobbyist couldnt test for it).

Second - I agree - there are various articles that suggest certain things - but - one point I tried to make - is that even successful tanks vary considerably - on their bacterial content - and diversity - so maybe a lab study on metabolism is not as applicable as you think it might be?

We've kinda hit an impasse because I've tried to answer this same question from you a bunch of times already. So I'll just leave it at this-acetate will grow bacteria in every single tank on the planet, and it will sequester nutrients in every tank on the planet. Do you think it is because every tank on the planet has the same bacterial strains, or not?

So I'm going to address the significant degree thing in a second here, first I just want to get back to info that the readers of a nitrate thread want to hear.

First thing to introduce is the fact that our tanks are carbon limited so we get significant (measurable) nitrate production. Depending on your methods of care you might run from hobby test 0 to some people running like 100 or more. So if we just glance over at the concentration of nitrate on a nice pristine reef in Curacao for example it is about 0.5uM because the ocean is nitrogen limited. This is equivalent to 31 ug/L or 0.03 ppm nitrate. A zero on that trusty hobby test, even the lr one Hanna just came out with won't detect this level with any accuracy. So if you're running a conservative 5ppm or so that is 167x the level of a reef. This is a massive difference and which for some reason on here people will argue doesn't matter even while scientists in the field are trying to figure out ways to block fertilizer runoff from destroying reefs around the world. Why are they destroying reefs, well apparently it's not just eutrophication in the direct runoff but there is others variables at play such as in the above paper which implicates higher nitrate levels with coral bleaching under thermal stress.

quick digression about eutrophication:
So when @Dan_P says raising nitrate levels for cyanobacteria does not control mat forming by the mechanism stated, well I agree, it's a complete red herring. If you look at tone of the big massive issues with fertilizer runoff is the uncontrolled growth of the cyanobacterial population and the release of toxins to the surrounding areas. So which makes more sense? Adding nitrate to a tank suppresses cyanobacterial overgrowth or having lower levels of nitrate? Remember autotrophs like cyanobacteria are not carbon limited in your aquarium.

And as for the tests in this hobby and significance well for example lets say someone is running a barebottom tank ;) which has a total (aerobic or anaerobic) denitrifier population that converts 500 ug/L of nitrate/week to dinitrogen or nitrous oxide. Would you say this is 0? Of course not but our hobby kits would never detect anything like this, so this is a nonsignificant change. Yet this nonsignificant finding will add up to 26mg/L nitrate removed/year. Again with other organisms utilizing nitrate assimilation (which in essence is a type of denitrification) NO3 -- NH3 -- proteins and nucleotides, your not going to see any of this. I mean even the randomness of feeding is going to put you so far into the margin of error that detecting these underlying population is laughable to say the least. However it doesn't mean they are not there, in fact the literature suggests that having none of these processes going on would be much more unlikely :D

 

[Dan_P]

I guess I dont believe in using the Redfield ratio in this way - but - for sure - N and P are not 'leftovers' - per se - right? I mean - how would glycolysis work without N and P (and C)

The point is that a large fraction of biomass is turned into CO2 when eaten. The organism cannot use all the N and P associated with the carbon used for energy generation. It simply cannot use all of the N and P without more C to make biomass, no matter what stoichiometric ratio you use. Us heterotrophs dump N and P after eating, that’s all.

 

[MnFish1]

We've kinda hit an impasse because I've tried to answer this same question from you a bunch of times already. So I'll just leave it at this-acetate will grow bacteria in every single tank on the planet, and it will sequester nutrients in every tank on the planet. Do you think it is because every tank on the planet has the same bacterial strains, or not?

So I'm going to address the significant degree thing in a second here, first I just want to get back to info that the readers of a nitrate thread want to hear.

First thing to introduce is the fact that our tanks are carbon limited so we get significant (measurable) nitrate production. Depending on your methods of care you might run from hobby test 0 to some people running like 100 or more. So if we just glance over at the concentration of nitrate on a nice pristine reef in Curacao for example it is about 0.5uM because the ocean is nitrogen limited. This is equivalent to 31 ug/L or 0.03 ppm nitrate. A zero on that trusty hobby test, even the lr one Hanna just came out with won't detect this level with any accuracy. So if you're running a conservative 5ppm or so that is 167x the level of a reef. This is a massive difference and which for some reason on here people will argue doesn't matter even while scientists in the field are trying to figure out ways to block fertilizer runoff from destroying reefs around the world. Why are they destroying reefs, well apparently it's not just eutrophication in the direct runoff but there is others variables at play such as in the above paper which implicates higher nitrate levels with coral bleaching under thermal stress.

quick digression about eutrophication:
So when @Dan_P says raising nitrate levels for cyanobacteria does not control mat forming by the mechanism stated, well I agree, it's a complete red herring. If you look at tone of the big massive issues with fertilizer runoff is the uncontrolled growth of the cyanobacterial population and the release of toxins to the surrounding areas. So which makes more sense? Adding nitrate to a tank suppresses cyanobacterial overgrowth or having lower levels of nitrate? Remember autotrophs like cyanobacteria are not carbon limited in your aquarium.

And as for the tests in this hobby and significance well for example lets say someone is running a barebottom tank ;) which has a total (aerobic or anaerobic) denitrifier population that converts 500 ug/L of nitrate/week to dinitrogen or nitrous oxide. Would you say this is 0? Of course not but our hobby kits would never detect anything like this, so this is a nonsignificant change. Yet this nonsignificant finding will add up to 26mg/L nitrate removed/year. Again with other organisms utilizing nitrate assimilation (which in essence is a type of denitrification) NO3 -- NH3 -- proteins and nucleotides, your not going to see any of this. I mean even the randomness of feeding is going to put you so far into the margin of error that detecting these underlying population is laughable to say the least. However it doesn't mean they are not there, in fact the literature suggests that having none of these processes going on would be much more unlikely :D

FWIW - I never talked about acetate - but I agree. lets leave it :)

 

[MnFish1]

was thinking that myself. half the time I think they are real swedish expressions, and I think the other half @Lasse makes up for entertainment.

Right:)

 

[MnFish1]

FWIW - I never talked about acetate - but I agree. lets leave it :)

BTW - I asked a specific question - I asked do you believe in aerobic denitrification. No more no less - I agree you responded to many posts - but I asked that once. Can you just answer it?

 

[MnFish1]

FWIW - I never talked about acetate - but I agree. lets leave it :)

I will also ask - are you trying to promote a future product? It seemed that way yesterday..... I have no clue

 

[MnFish1]

The point is that a large fraction of biomass is turned into CO2 when eaten. The organism cannot use all the N and P associated with the carbon used for energy generation. It simply cannot use all of the N and P without more C to make biomass, no matter what stoichiometric ratio you use. Us heterotrophs dump N and P after eating, that’s all.

The Redfield ratio - to my understanding is not used this way

 

[Dan_P]

The Redfield ratio - to my understanding is not used this way

You may use any biomass stoichiometry you wish to demonstrate the concept.

 

[flampton]

BTW - I asked a specific question - I asked do you believe in aerobic denitrification. No more no less - I agree you responded to many posts - but I asked that once. Can you just answer it?

You're kidding me right now, read what I said two posts or so ago!

First is that aerobic denitrification is definitely happening but to be sure not in a way a hobbyist can test for.

I dont understand - so what you're really saying is 'aerobic denitrification doesnt occur to a significant degree'? It wasnt clear (that was the only reason I could think of that the 'hobbyist couldnt test for it).

Second - I agree - there are various articles that suggest certain things - but - one point I tried to make - is that even successful tanks vary considerably - on their bacterial content - and diversity - so maybe a lab study on metabolism is not as applicable as you think it might be?

You're being deliberately or unknowingly obtuse now. I've tried to help you and you just want to play some weird contrarian role of actually does science matter for our tanks? Maybe my tank works on magic and love

Peace

 

[MnFish1]

You may use any biomass stoichiometry you wish to demonstrate the concept.

Right meaning - that any post I might or might not make Is meaningless - every tank is different

 

[MnFish1]

You're kidding me right now, read what I said two posts or so ago!

First is that aerobic denitrification is definitely happening but to be sure not in a way a hobbyist can test for.



You're being deliberately or unknowingly obtuse now. I've tried to help you and you just want to play some weird contrarian role of actually does science matter for our tanks? Maybe my tank works on magic and love

Peace

Quote the post you mean - what I read was - read Randy's post. How are you helping me - I told you - I do none of the things you suggest - but - I have a successful tank?

 

[MnFish1]

The point is that a large fraction of biomass is turned into CO2 when eaten. The organism cannot use all the N and P associated with the carbon used for energy generation. It simply cannot use all of the N and P without more C to make biomass, no matter what stoichiometric ratio you use. Us heterotrophs dump N and P after eating, that’s all.

Lets start with what the Redfield ratio is - and is not? The Redfield ratio:
To explain this phenomena, Redfield initially proposed two mutually non-exclusive mechanisms:

I) The N:P in plankton tends towards the N:P composition of seawater. Specifically, phytoplankton species with different N and P requirements compete within the same medium and come to reflect the nutrient composition of the seawater.[1]

II) An equilibrium between seawater and planktonic nutrient pools is maintained through biotic feedback mechanisms.[1] [3] Redfield proposed a thermostat like scenario in which the activities of nitrogen fixers and denitrifiers keep the nitrate to phosphate ratio in the seawater near the requirements in the protoplasm.[4] Considering that at the time little was known about the composition of “protoplasm", or the bulk composition of phytoplankton, Redfield did not attempt to explain why its N:P ratio should be approximately 16:1.

In 1958, almost a quarter century after first discovering the ratios, Redfield leaned toward the latter mechanism in his manuscript, The Biological Control of Chemical Factors in the Environment.[3] Redfield proposed that the ratio of nitrogen to phosphorus in plankton resulted in the global ocean having a remarkably similar ratio of dissolved nitrate to phosphate(16:1). He considered how the cycles of not just N and P but also C and O could interact to result in this match.

There seems to be no rationale to aim for the Redfield ratio - in our tanks instead - our tanks will by themselves become the Redfield ratio - unless I'm misunderstanding.

 

[Lasse]

was thinking that myself. half the time I think they are real swedish expressions, and I think the other half @Lasse makes up for entertainment.

The one which live will see:p

Sincerely Lasse

 

[nornicle]

I am registering 0 nitrate and I’m worried but I do have some mown hair algae (tangs) and I feed three times a day with pellets covered with a little reef roids.

I have three tangs and three other fish in a 180 gallon. I assume nutrients are going in but they are being immediately utilised by algae etc.

I did notice some tissue recession on sps so have dropped my alk to 7.5 and hope it’s not the zero nitrates.

 

[Vanquishxxx]

How things have changed

 

[Kenneth Wingerter]

Here is another tip if you want to go that path. Bokashi composting is a very popular compost technique in Sweden these days. It use a microorganism blend that also content nonsulfur purple photosynthetic bacteria - it is traded as Effective Microorganisms. The microorganism Rhodopseudomonas palustris is present in this mix. This is one of the known luxury consumers of phosphorus. I have injected EM below my DSB and not crashed the aquaria yet :D. However - I have no possibility to get light in that environment for the moment - but I´m working on one idea that should combine anaerobe environment with light.

Sincerely Lasse

any interesting results since/so far?

 

[Lasse]

No - I have not worked on this issue so much lately. The NO3 concentration has gone down and the system looks like it is working. I will get more of these bacteria further on.

Sincerely Lasse