Sixty’s Understanding of Nutrient Ratios

[Randy Holmes-Farley]

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.

Consumption and addition of N and P often do not go together because there are processes such as denitrification or phosphate binding to mineral surfaces that use only one of the two.

That said, my main point is not that a ratio might not be useful to know. My point us that knowing the actual levels of N and P provide more information than a mere ratio, and can never lead to false conclusions like a ratio alone can.

 

[shwareefer]

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.

My po4 floats between .01 and .04 every week and my no3 will stay at 3ppm for a couple weeks or longer before falling off. I have to dose both to have any. 50 gallon frag tank with lots of corals and no fish. Is that useful for your test?

 

[sixty_reefer]

My po4 floats between .01 and .04 every week and my no3 will stay at 3ppm for a couple weeks or longer before falling off. I have to dose both to have any. 50 gallon frag tank with lots of corals and no fish. Is that useful for your test?

it will be useful, could you just add some extra info please.

If I understand it correctly you saying that:

po4 goes from 0.04 to 0.01 every week and dosing is needed to bring it back up to 0.04

No3 sits at 3 for a few week before falling down. Do you know to what value it falls down to?

because the system is fish less, I would need to ask if you are adding food to the coral in this tank or ghost feeding the tank.

 

[shwareefer]

it will be useful, could you just add some extra info please.

If I understand it correctly you saying that:

po4 goes from 0.04 to 0.01 every week and dosing is needed to bring it back up to 0.04

No3 sits at 3 for a few week before falling down. Do you know to what value it falls down to?

because the system is fish less, I would need to ask if you are adding food to the coral in this tank or ghost feeding the tank.

You understand correctIy. I do feed the corals LPS pellets and Reefroids once a week. I actually use the reefroids to get the measureable phosphate, not a phosphate additive ( i didn't know there was going to be quiz, lol). The pellets do not seem to effect phosphate that I can measure. I use neonitro for nitrates and usually in the third week it will fall to .5ppm. I'm using hanna for Phosphate measurements but I'm using Salifert for nitrates so there can be some ambiguity in the value ( I look through the side and divide by 10, looking through top is useless for low values).

 

[sixty_reefer]

You understand correctIy. I do feed the corals LPS pellets and Reefroids once a week. I actually use the reefroids to get the measureable phosphate, not a phosphate additive ( i didn't know there was going to be quiz, lol). The pellets do not seem to effect phosphate that I can measure. I use neonitro for nitrates and usually in the third week it will fall to .5ppm. I'm using hanna for Phosphate measurements but I'm using Salifert for nitrates so there can be some ambiguity in the value ( I look through the side and divide by 10, looking through top is useless for low values).

I had to ask as the ratios in our closed systems are fixed depending on what we add to the tank, the main source of C N and P comes from food and additives.

with the information you gave me I can conclude that your system has a abundance of Carbon and Nitrogen with Carbon being the one in more abundance and Phosphorus being the limited one.

to fix the ratio you could:

1: carry on dosing Nitrogen and Phosphorus

2: Find the source of carbon and reduce it

3: Ghost feed the tank with a food that has a higher content in Nitrogen and Phosphorus

4: Add fish to the system, start feeding the fish and evaluate the ratio in a few weeks after the addition.

Addition notes:

At the moment you have a low import low export system, you could ghost feed the system daily to increase import and fix the C N P ratio to do a high import high export system (ULN). The food C N P content will determine the tanks ratio so in your particular case you would need a food with a low C content to have the microbe population working for you. you would have to gradually build the feeding to let bacteria population grow gradually with the new amounts of nutrients added to the system.

It’s not rocket science and we all doing it already, I do apologise for anyone that was expecting a crazy formula out of this thread, I can only say which ones are in abundance or limited with no3 and po4 trends. this is my understanding of using ratios and nutrients limitations to help stabilise No3 and Po4 in our closed systems. Hope it helps.

there’s someone on here that is really good at calculating food content, with more information on the C N P of different foods and additives we could well be in a better place regarding nutrient control

 

[shwareefer]

I had to ask as the ratios in our closed systems are fixed depending on what we add to the tank, the main source of C N and P comes from food and additives.

with the information you gave me I can conclude that your system has a abundance of Carbon and Nitrogen with Carbon being the one in more abundance and Phosphorus being the limited one.

to fix the ratio you could:

1: carry on dosing Nitrogen and Phosphorus

2: Find the source of carbon and reduce it

3: Ghost feed the tank with a food that has a higher content in Nitrogen and Phosphorus

4: Add fish to the system, start feeding the fish and evaluate the ratio in a few weeks after the addition.

Addition notes:

At the moment you have a low import low export system, you could ghost feed the system daily to increase import and fix the C N P ratio to do a high import high export system (ULN). The food C N P content will determine the tanks ratio so in your particular case you would need a food with a low C content to have the microbe population working for you. you would have to gradually build the feeding to let bacteria population grow gradually with the new amounts of nutrients added to the system.

It’s not rocket science and we all doing it already, I do apologise for anyone that was expecting a crazy formula out of this thread, I can only say which ones are in abundance or limited with no3 and po4 trends. this is my understanding of using ratios and nutrients limitations to help stabilise No3 and Po4 in our closed systems. Hope it helps.

there’s someone on here that is really good at calculating food content, with more information on the C N P of different foods and additives we could well be in a better place regarding nutrient control

Wow that's really interesting and not what I was expecting. Are there naturally occurring carbon sources in closed systems or does it have to be something I'm adding?

 

[sixty_reefer]

Ratios is the rate our system deplete nutrients at a set rate if the C N and P are out of equilibrium will cause concentration of po4 and No3 to rise or lower. To stabilise Nutrients we can use a few generic information that will tell us why our nutrients (po4 and no3) are building up or decreasing.

examples of nutrient and they’re limitations:

po4 concentration going up
No3 stable

Meaning: the system has a abundance of phosphorus, Carbon and Nitrogen are on the right ratio.

fix: reduce phosphorus source or increase Carbon and Nitrogen


po4 concentration going down
No3 stable

meaning: the system is being limited by po4, Carbon and Nitrogen are at the right ratio

fix: increase po4 source or reduce Carbon and Nitrogen source


po4 stable
no3 stable

meaning: The tank is in equilibrium there’s nothing to fix

This are just a few examples, we only got two parameters making only a few possible scenarios, can post the others later on if there is any interest in it.
Anyone with knowledge could make a calculator out of this to be used as a guide line only.

 

[sixty_reefer]

Wow that's really interesting and not what I was expecting.

Thank you just trying to bring new things to a one sided debate normally

Are there naturally occurring carbon sources in closed systems or does it have to be something I'm adding?

Yes, macro and micro algae can use inorganic carbon from the atmosphere (co2) to produce organic carbon. In most systems carbon will be introduced by feeding or a additive (coral food and supplements)

 

[sixty_reefer]

Imo you could explain almost everything that happens in our aquariums using this as a template.

lets use another common issue in our reef regarding pest algae’s.

A closed system gets overrun with GHA:

looking at trends on this forum we see that po4 and No3 concentrations start to lower. Meaning that the system has had a recent increase of Carbon and Nitrogen in the water column with carbon being the highest. If the source of carbon and nitrogen is coming from the algae, shouldn’t we be trying to correct the ratio by adding Nitrogen and Phosphorus to keep the bio filter healthy denying the algae the nutrients that it needs to grow? If our biological filter weakens the algae will have plenty of ammonium to grow, if our biological filter is strong the ammonium will be used by the bacteria instead of the algae starving the GHA and killing it wile our system gets stronger.
the common practice of bringing the concentration of po4 and no3 down is just fuelling the algae wile weakening the system microbe population. Isn’t this the reason mature thanks with stable no3 and po4 have less algae problems than the systems were concentration of po4 and no3 are all over the place and most times limited.

this may sound crazy and I can see the grief coming although it does makes sense if you understand the closed systems ratios.

 

[Randy Holmes-Farley]

Wow that's really interesting and not what I was expecting. Are there naturally occurring carbon sources in closed systems or does it have to be something I'm adding?

I don’t see a reason to believe that there is any information bearing on organic carbon levels in the info you provided.

 

[shwareefer]

I don’t see a reason to believe that there is any information bearing on organic carbon levels in the info you provided.

Agreed and why I expressed surprise. However @sixty_reefer has suggested from the beginning that it could be extrapolated from knowing the po4 and no3 trends so I'm open to the possibility.

 

[sixty_reefer]

I don’t see a reason to believe that there is any information bearing on organic carbon levels in the info you provided.

Lps pellets and reef roids are high in nitrogen there will be organic carbon there to and I wouldn’t know what else the op adds to the tank, regardless of what he feeds the tank he’s concentration of po4 and No3 going down at different rates indicates that he’s over all systems is limited on phosphorus and it has a abundance of Carbon and Nitrogen with Carbon being the highest in abundance.
we don’t need absolute values of doc and N-doc or Nitrogen to see that there is a problem on the overhaul system ratio. Sometimes we just need a indication to make corrections to the nutrients.
If both concentrations are constant then the ratio is fine.

 

[shwareefer]

I wouldn’t know what else the op adds to the tank

You are the op, lol. I was only trying to facilitate the conversation. There's nothing really wrong with my system (observably).

 

[Randy Holmes-Farley]

Lps pellets and reef roids are high in nitrogen there will be organic carbon there to and I wouldn’t know what else the op adds to the tank, regardless of what he feeds the tank he’s concentration of po4 and No3 going down at different rates indicates that he’s over all systems is limited on phosphorus and it has a abundance of Carbon and Nitrogen with Carbon being the highest in abundance.
we don’t need absolute values of doc and N-doc or Nitrogen to see that there is a problem on the overhaul system ratio. Sometimes we just need a indication to make corrections to the nutrients.
If both concentrations are constant then the ratio is fine.

While I’m highly skeptical that you can assess P and N limitation from the provided info, there’s no info on carbon or his carbon export methods, so IMO, there’s no possible way to be making assessments of carbon levels in his tank just by knowing N and P.

 

[sixty_reefer]

You are the op, lol.

sorry my mistake

I was only trying to facilitate the conversation. There's nothing really wrong with my system (observably).

I know there’s nothing wrong with your system because you keep correcting it using N and P. All I’m saying is that there is room for improvement and stability

 

[sixty_reefer]

While I’m highly skeptical that you can assess P and N limitation form the provided info, there’s no info on carbon or his carbon export methods, so IMO, there’s no possible way to be making assessments of carbon levels in his tank just by knowing N and P.

I can do a indication of which is limited or in abundance by just looking at the concentration of no3 and po4 staying stable or going up and down. Using the ratios given by redfield as a guide line. If you know of a actual issue in a particular system that you have tested, give me the details of that thank an I will match my details with yours almost for sure using less tech. I won’t give numbers but I will be able to tell which ones are high, low or in equilibrium

 

[sixty_reefer]

I can do a indication of which is limited or in abundance by just looking at the concentration of no3 and po4 staying stable or going up and down. Using the ratios given by redfield as a guide line. If you know of a actual issue in a particular system that you have tested, give me the details of that thank an I will match my details with yours almost for sure using less tech. I won’t give numbers but I will be able to tell which ones are high, low or in equilibrium

@Randy Holmes-Farley, do you know anyone that works in a public aquarium with access to this kind of data? That would be a good test to the ideology

 

[Pkunk35]

I had to ask as the ratios in our closed systems are fixed depending on what we add to the tank, the main source of C N and P comes from food and additives.

with the information you gave me I can conclude that your system has a abundance of Carbon and Nitrogen with Carbon being the one in more abundance and Phosphorus being the limited one.

to fix the ratio you could:

1: carry on dosing Nitrogen and Phosphorus

2: Find the source of carbon and reduce it

3: Ghost feed the tank with a food that has a higher content in Nitrogen and Phosphorus

4: Add fish to the system, start feeding the fish and evaluate the ratio in a few weeks after the addition.

Addition notes:

At the moment you have a low import low export system, you could ghost feed the system daily to increase import and fix the C N P ratio to do a high import high export system (ULN). The food C N P content will determine the tanks ratio so in your particular case you would need a food with a low C content to have the microbe population working for you. you would have to gradually build the feeding to let bacteria population grow gradually with the new amounts of nutrients added to the system.

It’s not rocket science and we all doing it already, I do apologise for anyone that was expecting a crazy formula out of this thread, I can only say which ones are in abundance or limited with no3 and po4 trends. this is my understanding of using ratios and nutrients limitations to help stabilise No3 and Po4 in our closed systems. Hope it helps.

there’s someone on here that is really good at calculating food content, with more information on the C N P of different foods and additives we could well be in a better place regarding nutrient control

hi just had some questions, redfield ratio is interesting but I too don’t see how it is useful for practical applications.

1) how do u know which foods have a higher nitrogen or phosphate concentration? Or How would we compare foods to each other as this answer states? I feed roids, brightwell coral foods, pe mysis, various flakes, etc. I’d love to know if there was a way to tell N vs P content.

2). What does “fixing” the ratio do? I’ve heard of color improvement for some (they all seem to be acropora keepers whom all seem to think everything they do affect their coral color)?

3). Will fixing this ratio, as the suggestions above, do you feel will make the ratios stop shifting? Is this “tank stability” over time (I guess we would call this getting an aquarium “dialed in” or “mature”)

4). Are we sure things consume in a redfield ratio? If randy is correct above that some macros/organisms utilize these parameters in a non-redfield ratio manner then he correctly assumes that only absolute values are going to matter when adjusting back to what is normal or “correct”.

interesting thread and just looking to expand on it!
And here’s a pic bc all threads are better with them:

 

[sixty_reefer]

hi just had some questions, redfield ratio is interesting but I too don’t see how it is useful for practical applications.

1) how do u know which foods have a higher nitrogen or phosphate concentration? Or How would we compare foods to each other as this answer states? I feed roids, brightwell coral foods, pe mysis, various flakes, etc. I’d love to know if there was a way to tell N vs P content.

We just at the beginning of something new, there is no ratio content on foods because we not been asking suppliers for it. In a near future would be nice to see food labels with different ratios specified to accommodate our system needs.

2). What does “fixing” the ratio do? I’ve heard of color improvement for some (they all seem to be acropora keepers whom all seem to think everything they do affect their coral color)?

“fixing the ratio” on this thread means balancing nutrients to be depleted by the system at a stable rate. Keeping the concentration of no3 and po4 constant every day, without up and down fluctuations that will end up in higher or lower concentration of po4 and no3 left in a system after the system used what they needed.

3). Will fixing this ratio, as the suggestions above, do you feel will make the ratios stop shifting? Is this “tank stability” over time (I guess we would call this getting an aquarium “dialed in” or “mature”)

“fixing the ratio” will ensure that a particular system is receiving different nutrients in the amounts required not leaving left overs to build up concentration of no3 and po4. Having a constant reading of concentrated po4 and no3 can avoid pest algaes to overgrow tanks plus other benefits that come with stable nutrients.

4). Are we sure things consume in a redfield ratio? If randy is correct above that some macros/organisms utilize these parameters in a non-redfield ratio manner then he correctly assumes that only absolute values are going to matter when adjusting back to what is normal or “correct”.
interesting thread and just looking to expand on it!
And here’s a pic bc all threads are better with them:

No, I’m not sure if the redfield ratio is correct but it is close enough to determine what nutrient or nutrients are being limited or in abundance on our closed systems for the overall demand of the system. Not for a particular living form living in our system. This method is for the whole system demand and gives you a indication of which is out of whack.

absolute values of C N and P don’t matter as it’s confusing and will be different in every system. What will be the same in every system is the shifts in concentration of po4 and no3 and they’re trends of going up or down will tell us which of C N and P is out of balance, once you know which one is out of balance small changes can be done to adjust the stability of no3 and po4 using C N P sources.

 

[Randy Holmes-Farley]

@Randy Holmes-Farley, do you know anyone that works in a public aquarium with access to this kind of data? That would be a good test to the ideology

Sure.

A lot of limitation studies are also published, and they do not make assumptions based on ratios. They test it by adding N or P or both and see what happens to growth. In the same water, different organisms can have different limiting factors, and in some cases, something else such as iron is limiting.

You might send a pm to Thales here at REEF2REEF.