Sixty’s Understanding of Nutrient Ratios

sixty_reefer

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In this thread I will be using the abbreviation

C (carbon)
N (nitrogen)
P (phosphates)
The word “Parameters” will refer to no3 and Po4 only

At no given point I will be using the above abbreviations to describe parameters as it’s widely seen and confusing wend discussing ratios, Ratios are not parameters although parameters can be adjusted or balanced using Ratios. Ratios are used by oceanographers to discuss and deal with nutrient limitations. This limitations will have a great impact on a closed systems that are depending mostly on feeding as a sole source of import of C N and P to a closed system.

In this thread at no given point will N and P abbreviation used to describe a parameter

N doesn’t mean No3 (nitrate)
P doesn’t mean po4 (phosphates)

In salt water aquaria there’s only one ratio that I find useful for the hobby, the Microbe Ratio as a hole in a closed system which I suspect with my limited knowledge that it will be similar to the phytoplankton Ratio.
A way to use Ratios in our closed system would be having a knowledge on how the system behaves regarding parameters, we can have a suspicions on which of the three is limited in our tank or in abundance by keeping an eye on parameters.

A example that is commonly used in our hobby to use ratios would be carbon dosing.

Carbon dosing it used as a way do drop the parameters No3 and Po4, as more carbon is added to a closed system the no3 and po4 are reduced in a set ratio. (X) amount of carbon added will reduce (Y) amount of No3 and (Z) amount of po4, this is called a Ratio.

Carbon dosing can be expanded further, most reefers that choose to go by this method in most cases will be because high no3 is available in a system, once the desired parameters of no3 is reached the user normally reduce the amount of Carbon dosed or remove the carbon source altogether.

Are we using Ratios to a full potential in the hobby

no, I believe we aren’t using ratios to the full potential.

let’s imagine that after carbon dosing we were left with the fallowing parameters.

no3 of 5ppm
Po4 of 0.3ppm

this parameters would bother many due to the high po4.

In this situation we could carry on dosing carbon or increasing carbon source and additionally start dosing Nitrogen to reduce the po4 parameter using the Ratio.

How would it work:

lets imagine that the ratio is 8:2:1 C N P (to keep things simple) if the ratio of C and N added to a system is doubled the system would be now using/transforming twice as much phosphorus, limiting the phosphates available in a tank.

Dosing 8 parts of carbon and 4 pats of nitrogen will remove 2 parts of phosphorus.

other situations were a ratio could be implemented:

low po4 parameter, if a tank has a low po4 parameter is because the system is limited in phosphorus, meaning that that particular system has a abundance of C and N utilising the ratios a po4 source could be dosed to the system to bring the system back to balance/equilibrium.

Is there other methods to balance ratios?

yes, there are so many ways to bring parameters to a equilibrium. Will they be using the biological filter to a full potential that could be a discussion for another thread.

Can I have high or low parameters and still have a balanced ratio?

Yes, ratios are a good way to control parameters in a closed system, although ratios are not parameters. Ratios can be used to increase or decrease a parameter and if implemented correctly, stability will be constant.

we’re can I get C N and P solution?

Many sponsors on this forum will stock this solution.

I would just like to add that if you using sources of C N and P to do your research first, playing with microbes in a closed system will have great impact on thank inhabitants if they are overdosed. Play safe and read the instructions or research.

This is my vaguely understanding of Ratios am happy to discuss further below on the comments.
 
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sixty_reefer

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So what's the typical ratio for something like NOPOX?
I don’t know, I don’t know what’s the ratio of the pellet food, the ratio in frozen food, the ratio on the additive that you have just added to make your corals grow faster, I don’t know whats the ratio on the dying chaeto/macro algaes,

all i know is that the overall ratio on a environment follows redfield and although we can’t seem to have exact numbers at the moment for most of the individual factors at a hobby level, we can use parameters to understand witch of the 3 is limited in a closed system and implemented that knowledge to correct the limitations or abundance.
 
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sixty_reefer

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I'm not sure I completely understand the practical applications (it sounds like there are a lot of variables), but I do appreciate the writeup and will be following along with interest!
I would suppose that some of the most common applications would be in nutrient limitations, for example I see many tanks being limited in nitrates and bottom out causing all the issues that we know including dinoflagellates, coral starvation and beneficial bacteria going dormant.

now in a situation like this we’re only no3 goes down and phosphates stay constant or start to rise up will means that there is a excessive source of carbon being released in to the closed system,

the source of carbon could be as simple as replacing a food that is high in carbon for a food that has less available carbon etc…

the end user that has low to none no3 has two options now, look into what’s causing the excessive carbon in the system and do changes on food, additives or other sources of carbon or add no3 to the system to try and raise no3 and create an equilibrium on the ratio.

this information is known to us thanks to ratios and studies on nutrient limitations

Edit: note that I’ve mentioned that in this situation phosphates would be constant or rising after no3 hitting zero. The reason this happens is because there isn’t nitrates available to keep the ratio going.
 
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sixty_reefer

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Thought it is worth to add the link of this thread as it’s from a related discussion over the limitations of nutrients

 
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sixty_reefer

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If we, as salt water enthusiasts can’t understand the effects of nutrient limitations on our closed systems, what’s the chances we can explain to the rest of the world the effects of raised carbon in our oceans ecosystem.
 

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Well, to start off: MICROBES RULE!!!!

Problem I see is we can't test for Particulate Organic C, N or P. We can also can't test for Dissolved Organic C, N or P. I don't see how we can get any idea of ratios when there's so much we can't test for.

As far as adding labile DOC, aka carbon dosing, I certainly wouldn't be adding it to a reef system. Excess Labile DOC is what killing off coral reefs either directly by altering the microbial stuff in coral microbiomes or indirectly with sponges creating a feedback loop benefiting algae over corals.
 
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sixty_reefer

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Well, to start off: MICROBES RULE!!!!

Problem I see is we can't test for Particulate Organic C, N or P. We can also can't test for Dissolved Organic C, N or P. I don't see how we can get any idea of ratios when there's so much we can't test for.
yay for microbes lol

We can test it’s called Triton N-Doc

Is it helpful? Not in my view as we can’t account for the amount of microbes in a system or how much a algae bed is using those nutrients or how much of C N P are added in the daily feed of a particular system. Although we don’t know any of the above it doesn’t really matter to apply the knowledge of nutrients limitation using redfield as a guide line. Any situation on a reef tank involving no3 and po4 limitations or abundance can be answered using knowledge of nutrient limitations were redfield is used as a guide line.


As far as adding labile DOC, aka carbon dosing, I certainly wouldn't be adding it to a reef system. Excess Labile DOC is what killing off coral reefs either directly by altering the microbial stuff in coral microbiomes or indirectly with sponges creating a feedback loop benefiting algae over corals.

the thing is we add it to our reefs everyday under different forms if there wasn’t carbon available we would have microbes supporting life in our closed systems. The issues start went C N and P became limited or in abundance as in different ways they will affect no3 and po4 depending which one is limited.

to find which one is limited we only need the po4 and no3 parameters
 

Randy Holmes-Farley

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IMO, there is never a scenario in a reef tank where just knowing the ratio of N, C, and P is useful. Never.

One must also know the absolute values to make any sort of interpretation , and if you must know the absolute values, why not just use them?
 

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this information is known to us thanks to ratios and studies on nutrient limitations

I completely disagree. Ratios cannot tell us what is limiting. Absolute values can.
 
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sixty_reefer

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IMO, there is never a scenario in a reef tank where just knowing the ratio of N, C, and P is useful. Never.

One must also know the absolute values to make any sort of interpretation , and if you must know the absolute values, why not just use them?
Why don’t we test it now, give me any information about the no3 and po4 trend on a particular tank and I will do a effort to tell you which one is limiting the tank.
 

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Why don’t we test it now, give me any information about the no3 and po4 trend on a particular tank and I will do a effort to tell you which one is limiting the tank.

Lol

you already failed, even if you knew the actual values. Published literature shows that at the same N and P in seawater, some macroalgae are N limited, and some are P limited. One ratio, and more importantly, same exact everything, different limitations.

As to your test, not sure how it would be graded since we’d need data on what was limiting at the ratio I gave for any absolute concentrations I wanted them to be.

But if you want to try, assume it is exactly the Redfield ratio. Without knowing anything else, what limits primary production of photosynthetic organisms?
 
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sixty_reefer

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Lol

you already failed, even if you knew the actual values. Published literature shows that at the same N and P in seawater, some macroalgae are N limited, and some are P limited. One ratio, and more importantly, same exact everything, different limitations.

As to your test, not sure how it would be graded since we’d need data on what was limiting at the ratio I gave for any absolute concentrations I wanted them to be.

But if you want to try, assume it is exactly the Redfield ratio. Without knowing anything else, what limits primary production of photosynthetic organisms?
It doesn’t work like that, I need no3 and po4 values to tell which one of the 3 is limited in closed system, it doesn’t matter if you got algae bed, coral or fish. If you can tell me the po4 and no3 fluctuations I can tell using nutrient limitation knowledge which one is limited in that particular tank for all tank inhabitants.
 

Randy Holmes-Farley

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It doesn’t work like that, I need no3 and po4 values to tell which one of the 3 is limited in closed system, it doesn’t matter if you got algae bed, coral or fish. If you can tell me the po4 and no3 fluctuations I can tell using nutrient limitation knowledge which one is limited in that particular tank for all tank inhabitants.

Lol, I don’t believe anyone can do that since it varies by species.

ok, try this:

total dissolved N : P of 18.5 (mole ratio).

is N or P limiting macroalgae growth?

Same question at N : P of 4.1.
 
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sixty_reefer

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Lol, I don’t believe anyone can do that since it varies by species.

ok, try this:

total dissolved N : P of 18.5 (mole ratio).

is N or P limiting macroalgae growth?

Same question at N : P of 4.1.
It’s not going to work, is it? That’s not what I’ve asked you.
 

Randy Holmes-Farley

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It’s not going to work, is it? That’s not what I’ve asked you.

What did you ask? I don’t know what you mean by fluctuations.

since you cannot tell me what is limiting at the ratios I posed, what good are ratios?
 
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sixty_reefer

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What did you ask? I don’t know what you mean by fluctuations.

since you cannot tell me what is limiting at the ratios I posed, what good are ratios?

let me try and do a different analogy

coral use/transform Ca and dkh at a set rate in a closed system. (Most of the time)

Let’s say that i got a 1 gallon tank with 1 coral and you have a 100 gallon tank with 100 corals of similar size, we both keep our ca at 440 and we both keep our dkh at 7.

your tank will be using/transforming much more Ca and dkh than mine, correct?
But we would be both using a very similar ratio of dkh and Ca for the amount of coral in our very different tanks.

The same applies here, I believe that there is a nutrient ratio that is similar in all of our tanks, it may well not be the phytoplankton ratio but it will be very close to it. Because I can be running my 1 gallon tank at the exact same no3 and po4 that you run your 100 gallon tank, this would mean that the ratio or rate of the usage/transformation of Carbon, Nitrogen and phosphorus between our tanks would be very similar if not identical. The only difference would be that you would have C N P in higher number’s than mine.
 
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