P&N Ratios Balancing the Equation

[Bruce Burnett]

So when it was stated that iron and manganese were needed as they get consumed not magnesium.
Also I understand what Randy was saying. If you have set numbers that should be obtained why would a ration matter if the required numbers are to high what difference does the ratio make.

 

[sixty_reefer]

So when it was stated that iron and manganese were needed as they get consumed not magnesium.
Also I understand what Randy was saying. If you have set numbers that should be obtained why would a ration matter if the required numbers are to high what difference does the ratio make.

A ratio matter if you can understand where the ratio is, the ratio is not in the concentration of po4 and no3, redfield ratio is how import export works in a tank we been using it for years since the hobby started why is so difficult to see?
Redfield is equivalent to the rate or ratio that a salt water tank depletes nutrients

 

[mathewdura]

I do ATI tests monthly and I can tell you that the Hanna hr is lower then the ATI my Hanna is tell me that my no3 is at 0.15 and 0.20 and the ATi test is 22.58

 

[sixty_reefer]

I do ATI tests monthly and I can tell you that the Hanna hr is lower then the ATI my Hanna is tell me that my no3 is at 0.15 and 0.20 and the ATi test is 22.58

The concentration of po4 in a tank is not important really

 

[Randy Holmes-Farley Verified Community Expert]

A ratio matter if you can understand where the ratio is, the ratio is not in the concentration of po4 and no3, redfield ratio is how import export works in a tank we been using it for years since the hobby started why is so difficult to see?
Redfield is equivalent to the rate or ratio that a salt water tank depletes nutrients

IMO, that's the most significant flaw in your theory.

Neither addition nor consumption in a reef tank needs to be anything close to the Redfield ratio.

 

[Randy Holmes-Farley Verified Community Expert]

The concentration of po4 in a tank is not important really

Do you actually mean what you wrote? That the level cannot ever be too low or too high for optimal functioning of a reef tank? 0.000000000001 ppm phosphate is fine?

 

[sixty_reefer]

Do you actually mean what you wrote? That the level cannot ever be too low or too high for optimal functioning of a reef tank? 0.000000000001 ppm phosphate is fine?

For that matter even 0.0000000000000000 although you wouldn’t be able to read the shifts in po4, wend you testing po4 in a reef tank you only getting an idea of what’s left after all tank inhabitants had they’re consumption or utilised it. You not measuring what you have added to the tank with the food.

that number would be worrying only if you not importing nutrients to the system

 

[sixty_reefer]

IMO, that's the most significant flaw in your theory.

Neither addition nor consumption in a reef tank needs to be anything close to the Redfield ratio.

Are you sure of this? I can relate almost every thing regarding nutrients limitations in a saltwater system or in a ecosystem to redfield

 

[Randy Holmes-Farley Verified Community Expert]

Are you sure of this?

Of course I'm sure.

You think it isn't true?

Denitrification consumes nitrate and not phosphate.

phosphate binding to or coming off of calcium carbonate surfaces involves only phosphate.

Some organisms accumulate considerable phosphate:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7888455/
The N : P ratio in reef organisms need not be any particular value (Redfield looked at phytoplankton). For example, even just looking at macroalgae, the N : P ratio varies a lot

https://web.archive.org/web/2004072...482/Kaneohe Bay algae N-P Larned Mar Biol.pdf
Table 2 shows that even in the few species of macroalgae they tested, the N : P ratio varies from 27:1(for Dictyosphaeria versluysii) to 200:1 (for Caulerpa sertularioides).

 

[sixty_reefer]

Of course I'm sure.

You think it isn't true?

Denitrification consumes nitrate and not phosphate.

phosphate binding to or coming off of calcium carbonate surfaces involves only phosphate.

Some organisms accumulate considerable phosphate:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7888455/
The N : P ratio in reef organisms need not be any particular value (Redfield looked at phytoplankton). For example, even just looking at macroalgae, the N : P ratio varies a lot

https://web.archive.org/web/2004072...482/Kaneohe Bay algae N-P Larned Mar Biol.pdf
Table 2 shows that even in the few species of macroalgae they tested, the N : P ratio varies from 27:1(for Dictyosphaeria versluysii) to 200:1 (for Caulerpa sertularioides).

I’m not doubting this papers, Unfortunately I don’t think we will reach an agreement, maybe we will have to revisit in a few years, one person can’t change the way the hole world sees things.
what it matters is that I understand it and this will a low me to fulfil a long waited dream of keeping NPS thriving in home aquaria.

 

[Bruce Burnett]

A ratio matter if you can understand where the ratio is, the ratio is not in the concentration of po4 and no3, redfield ratio is how import export works in a tank we been using it for years since the hobby started why is so difficult to see?
Redfield is equivalent to the rate or ratio that a salt water tank depletes nutrients

I am a bit dense but my understanding is the Redfield ratio was carbon: nitrogen: phosphate of bacteria in molecular weight not ppm. Also not the water or corals or fish. So in ppm I believe that works out to 10 times nitrates to phosphate. Now most people agree nitrates less than 10 and phosphates less than .1. That is 100 to 1. Some people run them much lower and some have them higher. If your tank is carbon limited you can add and increase bacteria population which if exported will reduce nitrates and some phosphates but Redfield ratio is not needed for that. I am just a reefer no chemist.
My current tank developed dino during early stages, something I never had before in 35 plus years of saltwater. I used dry marco rock. It was covering everything and starting to cover even sps frags. My test showed 0 nitrates and .02 phosphates which I know not possible. I added Brightwell nitrate to bring it up to 2 ppm. Reduced daytime lighting and used UV. Dino gone in two days but nitrates were then at 38ppm and phosphates were .32.
My numbers are still higher than I want them but slowly coming down. My ratio is still about 100 to one. Everything is growing tank is crystal clear. Only export on my tank is skimmer and Rox carbon, uv at night and some water changes. No filter socks or roller mat and I have sand bottom with a diamond goby. Most of the time if there was no shimmer you would think you were looking through air. I read where people are throwing Redfield ratio around and do not even know it has to be converted. Since the Redfield ratio is carbon, nitrate and phosphate, I do not believe there is a way for a reefer to even measure carbon.

 

[sixty_reefer]

I am a bit dense but my understanding is the Redfield ratio was carbon: nitrogen: phosphate of bacteria in molecular weight not ppm. Also not the water or corals or fish. So in ppm I believe that works out to 10 times nitrates to phosphate. Now most people agree nitrates less than 10 and phosphates less than .1. That is 100 to 1. Some people run them much lower and some have them higher. If your tank is carbon limited you can add and increase bacteria population which if exported will reduce nitrates and some phosphates but Redfield ratio is not needed for that. I am just a reefer no chemist.
My current tank developed dino during early stages, something I never had before in 35 plus years of saltwater. I used dry marco rock. It was covering everything and starting to cover even sps frags. My test showed 0 nitrates and .02 phosphates which I know not possible. I added Brightwell nitrate to bring it up to 2 ppm. Reduced daytime lighting and used UV. Dino gone in two days but nitrates were then at 38ppm and phosphates were .32.
My numbers are still higher than I want them but slowly coming down. My ratio is still about 100 to one. Everything is growing tank is crystal clear. Only export on my tank is skimmer and Rox carbon, uv at night and some water changes. No filter socks or roller mat and I have sand bottom with a diamond goby. Most of the time if there was no shimmer you would think you were looking through air. I read where people are throwing Redfield ratio around and do not even know it has to be converted. Since the Redfield ratio is carbon, nitrate and phosphate, I do not believe there is a way for a reefer to even measure carbon.

There’s 2 cows and 3 rabbits in a room, every night I give them diner, apples, strawberries and peaches.
Every morning you go to the same room and you see that there are 2 strawberries and 1 peach left every day

can you calculate the number of apples, strawberries and peaches the rabbits are eating?
can you calculate what the cows and the rabbits are eating using the data I gave you?

 

[Bruce Burnett]

There’s 2 cows and 3 rabbits in a room, every night I give them diner, apples, strawberries and peaches.
Every morning you go to the same room and you see that there are 2 strawberries and 1 peach left every day

can you calculate the number of apples, strawberries and peaches the rabbits are eating?
can you calculate what the cows and the rabbits are eating using the data I gave you?

What. I don't keep cows and rabbits in a room and that does not give me any kind of ratio. That just tells me I am over feeding a room full of animals. Does not tell me who is eating what. Maybe only one of them even likes strawberries. Maybe none of those foods are even healthy for them. I have learned nothing from keeping and feeding unrelated animals in a room.

 

[sixty_reefer]

What. I don't keep cows and rabbits in a room and that does not give me any kind of ratio. That just tells me I am over feeding a room full of animals. Does not tell me who is eating what. Maybe only one of them even likes strawberries. Maybe none of those foods are even healthy for them. I have learned nothing from keeping and feeding unrelated animals in a room.

Exactly, measuring left overs don’t have any contribution to the animals health. That’s my point.

what if I told you now that the average ratio for all animals in that room is 8 : 3 : 1 apples : strawberries : peaches

I don’t want a number just want to see if is possible to do a approximate calculation for all animals in that room are eating.

 

[Bruce Burnett]

Exactly, measuring left overs don’t have any contribution to the animals health. That’s my point.

what if I told you now that the average ratio for all animals in that room is 8 : 3 : 1 apples : strawberries : peaches

I don’t want a number just want to see if is possible to do a approximate calculation for all animals in that room are eating.

But how does any of this relate to the Redfield ratio. Each individual species we keep in out tank has different requirements. People say mushrooms are easy beginner corals. They are not easy to keep in an all SPS low nutrient tank. Obviously how one feeds can effect export requirements and how aggressive one exports can change how one feeds. There are a number of ways for exporting and many use multiple ways. Still means nothing about the ratios in bacteria or phytoplankton. Almost every export or consumption of phosphates and nitrates are different. Algae scrubbers do a decent job of removing both but when either one gets to low the algae stops growing.

 

[sixty_reefer]

But how does any of this relate to the Redfield ratio. Each individual species we keep in out tank has different requirements. People say mushrooms are easy beginner corals. They are not easy to keep in an all SPS low nutrient tank. Obviously how one feeds can effect export requirements and how aggressive one exports can change how one feeds. There are a number of ways for exporting and many use multiple ways. Still means nothing about the ratios in bacteria or phytoplankton. Almost every export or consumption of phosphates and nitrates are different. Algae scrubbers do a decent job of removing both but when either one gets to low the algae stops growing.

I was just about to do a point, as you said before, looking at left overs is pointless, this translates directly in to measuring no3 and po4 as they are the left overs from the night feed. Measuring them don’t tell me what nutrients gone in that system or what nutrients are available in the system, all is telling us is that we got x and y left over.

using redfield ratio for phytoplankton which by the way is the closest we got to the ocean water we can have a approximate idea of from the block of frozen food I regularly feed a tank what’s being used by the bacteria living in it as bacteria is the one fixing the ratios in salt water.

 

[jda]

I get that it is a number and people can focus on those, but the details matter much more. If it helps, Redfield might be raw data point. Data is worthless (alone) except that you need it to sometimes move beyond. Data needs to be turned into information by a smart human to be of any value, but information is still not too terribly valuable in a lot of cases. Experience, experts and time turn information into knowledge. Knowledge is worth something. There is nothing beyond redfield being a data point except in the one known instance that it was studied - there is some information there on phyto. It is unfortunate that it is named redfield - if was named the phyto ratio, then this would never get talked about. I am going to start referring to it as Redfield/Phyto Ratio - I welcome others to do the same.

I strongly suggest not using information or knowledge about one topic and assuming that it is more that just a raw data point for another. IME/IMO, this is more dangerous than just not thinking about it. The 14.7 to 1 fuel to air ratio for an internal combustion engine is as close to knowledge as it gets for that particular purposed, but is not the ratio for snickers bars to oxygen to fuel a human in a marathon.

 

[Bruce Burnett]

I get that it is a number and people can focus on those, but the details matter much more. If it helps, Redfield might be raw data point. Data is worthless (alone) except that you need it to sometimes move beyond. Data needs to be turned into information by a smart human to be of any value, but information is still not too terribly valuable in a lot of cases. Experience, experts and time turn information into knowledge. Knowledge is worth something. There is nothing beyond redfield being a data point except in the one known instance that it was studied - there is some information there on phyto. It is unfortunate that it is named redfield - if was named the phyto ratio, then this would never get talked about. I am going to start referring to it as Redfield/Phyto Ratio - I welcome others to do the same.

I strongly suggest not using information or knowledge about one topic and assuming that it is more that just a raw data point for another. IME/IMO, this is more dangerous than just not thinking about it. The 14.7 to 1 fuel to air ratio for an internal combustion engine is as close to knowledge as it gets for that particular purposed, but is not the ratio for snickers bars to oxygen to fuel a human in a marathon.

Yes and even the ratio for an internal combustion engine changes by fuel type, compression and rpm. It would be great if everything was as simple as a single data point.

 

[Tony the Fish]

I thought reef tanks were focused on growing corals. Isn't the purpose of scrubbers to pull out excess nutrients. Why would I dose to increase production of the turf scrubber ?

 

[Bruce Burnett]

I thought reef tanks were focused on growing corals. Isn't the purpose of scrubbers to pull out excess nutrients. Why would I dose to increase production of the turf scrubber ?

Used to pull out nitrates and phosphates. So if algae production stops and you have excess nitrates and phosphates you need to fix what is limiting growth which could be iron or manganese. When nutrients get low enough you shorten the lighting period so that levels are maintained.