Sixty’s Understanding of Nutrient Ratios

[sixty_reefer]

Interesting discussion. Not sure any questions have been answered though.

Some important information missing from this conversation so far is an actual calculation of C:N for a system before and after a visually observable problem is resolved, for example, nuisance algae growth. That would really be interesting. Even showing how changing the C:N ratio of the food solved a nuisance algae problem.

The notion of nutrient balance is well known in aquaculture where closed systems are used. In this case, carbon is added to the feed to ensure that all the nitrogen can be converted to biomass, such as bacteria, rather than accumulate as nitrate in the water. Sound like carbon dosing?

That’s the point Dan, redfield is nothing new we have been using it for years, the only difference is that some implement it better than others unaware of it, carbon dosing is one of the several methods to fix the ratio in redfield.

why does a saltwater aquarist choose to implement carbon dosing? What’s happening in our tank regarding nutrient to make do that decision?

@Dan_P stay with me and i’ll show you the connection in the next few comments.

 

[sixty_reefer]

@Dan_P

the reason every one carbon doses is because of a raise in nitrates, does everyone following agree?

Could I guess the outcome of Carbon dosing using redfield?

let’s try every one knows the ratio right

106 : 16 : 1

Now lets increase N in the ratio as that’s what our tank is telling us we got high nitrates in our tank let’s double N just for

guide ratio 106 : 16 : 1
What our system may be 106 : 32 : 1

how do we fix the ratio? Increase carbon Right?

guide ratio 106 : 16 : 1

system after adding carbon 212 : 32 : 1

the system now is is in balance on the C and N at this point the nitrates won’t come down but you can see that C and N are double of the P meaning at this point Phosphates start to come down

let’s add more carbon ( that’s what we do slowly increase vodka or other carbon sources)

guide ratio 106 : 16 : 1

after some more Carbon 318 : 32 :1

now C is three times more available N is two times and P is still 1

what do we see happening in our systems

nitrates start to come down and at this point the phosphates reduction is becoming more noticeable.

isn’t this what happens in carbon dosing, nitrates and phosphates reduction, how did I just guess what would happen whith carbon dosing using redfield as a guide line, did I just got lucky? I assure you all that am not going crazy. What would happen if carbon dosing is not reduced or stopped after a wile? Would no3 and po4 hit zero at some point if a abundance of Carbon is available in a system?

 

[Nano sapiens]

Sorry you got it so wrong, there’s no ratio between the concentration of po4 and no3. That’s why we all have success with different parameters/ concentration

I'm sorry, on face value your statement indicates that you misunderstand what a ratio is:

Ratio: 'The indicated quotient of two mathematical expressions. b : the relationship in quantity, amount, or size between two or more things : proportion.'

By definition: The Redfield ratio or Redfield stoichiometry is the consistent atomic ratio of carbon, nitrogen and phosphorus found in marine phytoplankton and throughout the deep oceans

From what I can gather (and I've really tried to make scientific sense of your proposal), you are attempting to convince readers that if your C, N and P levels are stable over an extended time period, your system now reflects the 'real' Redfield ratio (is there a 'fake' Redfield ratio???). Based on the proper scientific definition of a ratio, how can one proclaim this as fact without knowing what the actual numbers are?

the real redfield relationship is on the import export relationship in our tanks that can’t be quantified, but it is very similar in all of our different systems.

From what I can ascertain, you are making an assumption:

"the real redfield relationship is on the import export relationship in our tanks that can’t be quantified, but it is very similar in all of our different systems."

that seems plausible to you and then are attempting to convince people that it is indeed factual. Science is based on quantifiable and repeatable testing results, but here you even say '..can't be quantified...'. If we buy into this, then we must believe that all our systems utilize C, N & P in the same or similar proportions to the Redfield ratio. At best, what we have here is that one can believe this on faith, or not.

Consider the wise quote below from your esteemed British scientist, Lord Kelvin:

"When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind: it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.'.​

The po4 and no3 that we can measure is the left over dinner from all thank inhabitant at the point the environment is tested. We can’t make a ratio out of left over diner but we can make a ratio on what the tank depleted. If you can understand what I just said you can understand redfield correctly.

Ok, let's take a look at the Redfield definition once again:

The Redfield ratio or Redfield stoichiometry is the consistent atomic ratio of carbon, nitrogen and phosphorus found in marine phytoplankton and throughout the deep oceans

Let me ask you this. What do you think scientists were measuring 'throughout the deep waters'? They were measuring the C, N and P ratio 'leftover dinner' (as you put it) just like we can measure in our aquarium water. And they found the phytoplankton and the 'leftover dinner' to have basically the same C, N and P ratio. Why? I would suggest that they were really measuring mostly the C, N and P of the million or so microorganisms per cubic cm of ocean water.

Which brings us back to the realization that our captive reef systems are not like the ocean in many ways and should make one question whether the Redfield ratio is of any significant importance in regards to our reef aquaria.


Ralph.

 

[sixty_reefer]

I'm sorry, on face value your statement indicates that you misunderstand what a ratio is:

Ratio: 'The indicated quotient of two mathematical expressions. b : the relationship in quantity, amount, or size between two or more things : proportion.'

By definition: The Redfield ratio or Redfield stoichiometry is the consistent atomic ratio of carbon, nitrogen and phosphorus found in marine phytoplankton and throughout the deep oceans

From what I can gather (and I've really tried to make scientific sense of your proposal), you are attempting to convince readers that if your C, N and P levels are stable over an extended time period, your system now reflects the 'real' Redfield ratio (is there a 'fake' Redfield ratio???). Based on the proper scientific definition of a ratio, how can one proclaim this as fact without knowing what the actual numbers are?



From what I can ascertain, you are making an assumption:

"the real redfield relationship is on the import export relationship in our tanks that can’t be quantified, but it is very similar in all of our different systems."

that seems plausible to you and then are attempting to convince people that it is indeed factual. Science is based on quantifiable and repeatable testing results, but here you even say '..can't be quantified...'. If we buy into this, then we must believe that all our systems utilize C, N & P in the same or similar proportions to the Redfield ratio. At best, what we have here is that one can believe this on faith, or not.

Consider the wise quote below from your esteemed British scientist, Lord Kelvin:

"When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind: it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.'.​

Ok, let's take a look at the Redfield definition once again:

The Redfield ratio or Redfield stoichiometry is the consistent atomic ratio of carbon, nitrogen and phosphorus found in marine phytoplankton and throughout the deep oceans

Let me ask you this. What do you think scientists were measuring 'throughout the deep waters'? They were measuring the C, N and P ratio 'leftover dinner' (as you put it) just like we can measure in our aquarium water. And they found the phytoplankton and the 'leftover dinner' to have basically the same C, N and P ratio. Why? I would suggest that they were really measuring mostly the C, N and P of the million or so microorganisms per cubic cm of ocean water.

Which brings us back to the realization that our captive reef systems are not like the ocean in many ways and should make one question whether the Redfield ratio is of any significant importance in regards to our reef aquaria.


Ralph.

You sound like you know what you talking about, I will ask you the same that I’ve asked before to Randy.

test my theory, give me the no3 and po4 shifts and i’ll tell you what limited or in abundance in that system or ecosystem.

what you got to loose?

 

[Nano sapiens]

You sound like you know what you talking about, I will ask you the same that I’ve asked before to Randy.

Perhaps, perhaps not . What I've learned over my 50 years of keeping aquariums is that it's very easy to deduce something via cause and effect, only to be proven incorrect later on. The old saying 'correlation does not imply causation' is something I try and remember.

test my theory, give me the no3 and po4 shifts and i’ll tell you what limited or in abundance in that system or ecosystem.

what you got to loose?

Quite honestly, I could not give you a better answer than Randy's:

"I gave you two N : P ratios that I knew the answer for multiple organisms and you declined to say what was limiting because you wanted more info. Hence, ratios are apparently not adequate for your method.

then you made some predictions of what was limiting for a reefer who posted, but no one knows if the prediction is better than a coin flip since the answer isn’t known for his tank.

Do your prediction have merit? No one knows. There’s no supporting data of any kind."

 

[sixty_reefer]

Perhaps, perhaps not . What I've learned over my 50 years of keeping aquariums is that it's very easy to deduce something via cause and effect, only to be proven incorrect later on. The old saying 'correlation does not imply causation' is something I try and remember.



Quite honestly, I could not give you a better answer than Randy's:

"I gave you two N : P ratios that I knew the answer for multiple organisms and you declined to say what was limiting because you wanted more info. Hence, ratios are apparently not adequate for your method.

then you made some predictions of what was limiting for a reefer who posted, but no one knows if the prediction is better than a coin flip since the answer isn’t known for his tank.

Do your prediction have merit? No one knows. There’s no supporting data of any kind."

If you can’t test me how can you assume that I’m wrong? Randy gave me absolute N : P he didn’t gave me po4 and No3 shifts.

try and test me with your tank, give me the po4 and no3 shifts of a particular situation you had and i’ll see if the multi options that come out of it is something you did to stabilise your no3 and po4

 

[Wasabiroot]

I'm so confused. A ratio that isn't a ratio that isn't known isn't a ratio, it's an arbitrary number with no hypothesis associated. Maybe the language of ratio is becoming a bit of a red herring. Is there a way to rephrase with different terminology?

I'm also struggling to see how many outside factors (i.e. dosing, just added food the previous night, skimmer overflowed) don't then require some sort of control. Not to mention we only measure parameters at infrequent points but the numbers may be fluctuating more than measured, and possibly in the opposite directions expected, muddying data. Hope I made sense. For example, one tank might have a spike in nitrogen from 3 different unrelated sources that say nothing about what the aquarist added, say a dead snail etc.

 

[areefer01]

I'm so confused. A ratio that isn't a ratio that isn't known isn't a ratio, it's an arbitrary number with no hypothesis associated. Maybe the language of ratio is becoming a bit of a red herring. Is there a way to rephrase with different terminology?

I'm also struggling to see how many outside factors (i.e. dosing, just added food the previous night, skimmer overflowed) don't then require some sort of control. Not to mention we only measure parameters at infrequent points but the numbers may be fluctuating more than measured, and possibly in the opposite directions expected, muddying data. Hope I made sense. For example, one tank might have a spike in nitrogen from 3 different unrelated sources that say nothing about what the aquarist added, say a dead snail etc.

This was said years ago. The only reason today that hobbyist care about a number is because there is a test kit for it. If there wasn't a test no one would care. Sort of like a bear pooping in the forest.

 

[Wasabiroot]

"...If you can’t test me how can you assume that I’m wrong? Randy gave me absolute N : P he didn’t gave me po4 and No3 shifts."

I would say that if we can't test it then what is it really saying? It's your hypothesis, not ours. It needs to be designed in a way that we CAN test it since you created the hypothesis.

No shade intended. Burden of proof and all that jazz.

 

[Wasabiroot]

This was said years ago. The only reason today that hobbyist care about a number is because there is a test kit for it. If there wasn't a test no one would care. Sort of like a bear pooping in the forest.

I mean in this specific post. I'm aware of the Redfield ratio, but am also of the camp it's essentially non applicable to our tanks.

 

[Dcal]

I struggle to understand how it has any relevance to a hobbyist's aquarium. We aren't worried about optimal growth rates of phytoplankton or microbial population dynamics. Similarly, nearly no hobbyist has the necessary equipment (and accompanying precision) to gather meaningful data and what is the end goal of targeting Redfield ratios? Increased coral growth or limiting algae growth? Both have proven methods of resolution that don't involve calculating/accurately measuring nutrients to that level of precision.

Here's a pretty cool paper I found but IMO the importance of Redfield ratios in regards to reefs is relevant when considering large scale (time/space) shifts that can arise when corals are at their optimal or not so optimal growth rates rather than chasing it in a closed system that doesn't have the time for dominance shifts. https://scholarspace.manoa.hawaii.edu/bitstream/10125/2232/v48n3-234-246.pdf

and a big +1 to everything @Nano sapiens said

 

[sixty_reefer]

I'm so confused. A ratio that isn't a ratio that isn't known isn't a ratio, it's an arbitrary number with no hypothesis associated. Maybe the language of ratio is becoming a bit of a red herring. Is there a way to rephrase with different terminology?

Yes, could call it the preferred ratio for micro

I'm also struggling to see how many outside factors (i.e. dosing, just added food the previous night, skimmer overflowed) don't then require some sort of control. Not to mention we only measure parameters at infrequent points but the numbers may be fluctuating more than measured, and possibly in the opposite directions expected, muddying data. Hope I made sense. For example, one tank might have a spike in nitrogen from 3 different unrelated sources that say nothing about what the aquarist added, say a dead snail etc.

it won’t matter on the big picture every thing in the system is taken into account in this theory

 

[sixty_reefer]

"...If you can’t test me how can you assume that I’m wrong? Randy gave me absolute N : P he didn’t gave me po4 and No3 shifts."

I would say that if we can't test it then what is it really saying? It's your hypothesis, not ours. It needs to be designed in a way that we CAN test it since you created the hypothesis.

No shade intended. Burden of proof and all that jazz.

Everyone can test it as long as you have a record of no3 and po4

 

[sixty_reefer]

I mean in this specific post. I'm aware of the Redfield ratio, but am also of the camp it's essentially non applicable to our tanks.

We all use redfield in a way or another we just don’t see it yet

 

[ReefGeezer]

I'm so confused. A ratio that isn't a ratio that isn't known isn't a ratio, it's an arbitrary number with no hypothesis associated. Maybe the language of ratio is becoming a bit of a red herring. Is there a way to rephrase with different terminology?

I'm also struggling to see how many outside factors (i.e. dosing, just added food the previous night, skimmer overflowed) don't then require some sort of control. Not to mention we only measure parameters at infrequent points but the numbers may be fluctuating more than measured, and possibly in the opposite directions expected, muddying data. Hope I made sense. For example, one tank might have a spike in nitrogen from 3 different unrelated sources that say nothing about what the aquarist added, say a dead snail etc.

Yea... The Redfield numbers just do not apply. However, understanding that some ratio exists is important when considering carbon dosing. It is understood that while N & P are required, the carbon dosing process uses N at a much higher rate than P. In understanding that, we can consider if the N condition in out tank is favorable for carbon dosing. Unfortunately, it is not only inorganic nitrate that is used/bound in carbon dosing process, so it is difficult to be very precise when making that consideration just based on a nitrate and phosphate test.

 

[areefer01]

We all use redfield in a way or another we just don’t see it yet

No, we don't.

 

[Nano sapiens]

If you can’t test me how can you assume that I’m wrong? Randy gave me absolute N : P he didn’t gave me po4 and No3 shifts.

try and test me with your tank, give me the po4 and no3 shifts of a particular situation you had and i’ll see if the multi options that come out of it is something you did to stabilise your no3 and po4

Ok, this is the only high nutrient event that I have experienced in recent memory (I don't use any man-made mechanical or chemical filtration, just LR and LS).

Due to an incorrect shipment, I had too many fish residing in my system (ergo too much food input/waste excretion for my export methods to properly deal with) which drove NO3 up to 30+ ppm. As an experiment, I implemented a gradual low dose carbon dosing plan using vinegar and increased water changes/detritus/bacteria removal since there is no skimmer. Within a few weeks this worked to drive NO3 down to 5 ppm. Some sensitive stony corals reacted negatively by partially bleaching, so I slowly discontinued carbon dosing. Since carbon dosing is known to also drive PO4 lower (PO4 has always been 'undetectable' in my system), this is likely to have been the cause of the bleaching and something that I was actually expecting.

I then let the system settle out over time at whatever NO3 level it wanted to (it stabilized at 10 ppm) and it's been that way for months now.

 

[sixty_reefer]

@Dan_P

the reason every one carbon doses is because of a raise in nitrates, does everyone following agree?

Could I guess the outcome of Carbon dosing using redfield?

let’s try every one knows the ratio right

106 : 16 : 1

Now lets increase N in the ratio as that’s what our tank is telling us we got high nitrates in our tank let’s double N just for

guide ratio 106 : 16 : 1
What our system may be 106 : 32 : 1

how do we fix the ratio? Increase carbon Right?

guide ratio 106 : 16 : 1

system after adding carbon 212 : 32 : 1

the system now is is in balance on the C and N at this point the nitrates won’t come down but you can see that C and N are double of the P meaning at this point Phosphates start to come down

let’s add more carbon ( that’s what we do slowly increase vodka or other carbon sources)

guide ratio 106 : 16 : 1

after some more Carbon 318 : 32 :1

now C is three times more available N is two times and P is still 1

what do we see happening in our systems

nitrates start to come down and at this point the phosphates reduction is becoming more noticeable.

isn’t this what happens in carbon dosing, nitrates and phosphates reduction, how did I just guess what would happen whith carbon dosing using redfield as a guide line, did I just got lucky? I assure you all that am not going crazy. What would happen if carbon dosing is not reduced or stopped after a wile? Would no3 and po4 hit zero at some point if a abundance of Carbon is available in a system?

Ok, this is the only high nutrient event that I have experienced in recent memory (I don't use any man-made mechanical or chemical filtration, just LR and LS).

Due to an incorrect shipment, I had too many fish residing in my system (ergo too much food input/waste excretion for my export methods to properly deal with) which drove NO3 up to 30+ ppm. As an experiment, I implemented a gradual low dose carbon dosing plan using vinegar and increased water changes/detritus/bacteria removal since there is no skimmer. Within a few weeks this worked to drive NO3 down to 5 ppm. Some sensitive stony corals reacted negatively by partially bleaching, so I slowly discontinued carbon dosing. Since carbon dosing is known to also drive PO4 lower (PO4 has always been 'undetectable' in my system), this is likely to have been the cause of the bleaching and something that I was actually expecting.

I then let the system settle out over time at whatever NO3 level it wanted to (it stabilized at 10 ppm) and it's been that way for months now.

Sorry for your losses, and I understand that it’s a sticky situation to be in wend you get a sudden rise in nitrates, you gave the full story so I don’t have anything to predict in this situation. A few comments back I’ve wrote the quote above on what happens wend carbon dosing, do you see a relation, according to the relation between the ratio and no3 and Po4 shifts your po4 bottom out.

 

[Freenow54]

For my own knowledge and to follow this. What exactly do you mean by Closed System

 

[sixty_reefer]

No, we don't.

How can you be so sure? Can you show me that we don’t use it?