Redfield Ratio Revisited – What are we doing wrong?

[Reef and Dive]

Yes it could but if we learn to connect our measurement to what we see in our aquarium and that we succeed to to hammer in the line - High values, okay - but how does your aquarium look? We maybe can succeed to connect the measurements with facts like this below. If I have a problem with Oscillatoria - maybe not going above the ratio of 7 : 1 according to N : P. But I agree - there is a lot of questions not solved. Does it matter which form the N is in. Can Oscillatoria utilize NO3-N or does it not have the enzymes needed. Most the N in the ratio be as NH3/NH4-N or as amino acids - N in order to be taken up by the cyanobacteria cell? Amino acids pass through single cells and protozoa cell walls as good as NH3/NH4



Sincerely Lasse

That’s an excellent point. I do not think ratios, maybe not even specific numbers, should be targeted. For the new reefer specific numbers should work as an easier goal.
But since we sometimes deal with some prolems that are harder to comprehend, a better understanding could help us interpret it’s origins.

Citing the original Redfield’s ratio on discussions brings many errors automatically, but refining that information with better understanding could help us.

 

[Thales]

Have

Have you seen a system that doesn't have an issue(nuisance algae, cyano, coral coloration,
coral growth, ect) with a big imbalance of N and P? I haven't.

Is nitrate of 50 and phosphate of .91 a big imbalance?

 

[sixty_reefer]

Its the same for some cyanobacteria as it is for some dinoflagellates. IMO - many times this two are misidentified for each other.

Sincerely Lasse

Imo they are completely different, one is a bacteria and the other an algae, I see Cyanobacteria often related to imbalance between n and p and dinoflagellates in extremely low n and p. Cyanobacteria for example, often burns out wend a the good bacteria repopulate

 

[sixty_reefer]

Yes we have, but we tried to keep track of scientific studies published on indexed science papers.

In comparison to the data we found Triton suggested ratios appear to be too high (in terms of nitrogen), so we found no scientific data supporting those numbers...

Have you found any scientific data showing how did they reached the redfield ratio by redfield?

 

[sixty_reefer]

Have

Have you seen a system that doesn't have an issue(nuisance algae, cyano, coral coloration,
coral growth, ect) with a big imbalance of N and P? I haven't. So yes I understand the ratio and what it meant for my tank. I have experienced first hand what a bad ratio does to a reef tank. Sure you can say "just shoot for ___ NO3 and ___ PO4", but those numbers usually fall within the recommended ratio numbers anyway. So it's essentially teaching someone to not learn for themselves and just remember a hard number. Which causes number chasing and headaches.

For example, if you experience a NO3 spike of 3ppm you can measure PO4 and see if it's acceptable in the ratio. Then you can take a breath, and not start doing some drastic changes to drop your NO3 because it's suddenly out of that hard number that was given to him by a member on these forums.

I personally just think it's a better approach to maintaining nutrient levels for a healthy tank versus chasing numbers for that hard number.

My reef, with low no3 and 1.9 po4 a good balance won’t give you good coral colour and health that comes from trace elements.

 

[Lasse]

Is nitrate of 50 and phosphate of .91 a big imbalance?

Its a ratio of 38:1 as NO3-N : P - not so bad as a ratio and I think that your aquarium work well @Thales. In my aquarium - i have a ratio between NO3-N and other N -species of 1:1 - Seen as total N : P - you may be around 80 : 1. Triton have 147 : 1 as their target value as total N : total P. I have lower total concentration - nearly a tenfold lower - but my ratio is nearly the same as yours.

Imo they are completely different, one is a bacteria and the other an algae, I see Cyanobacteria often related to imbalance between n and p and dinoflagellates in extremely low n and p. Cyanobacteria for example, often burns out wend a the good bacteria repopulate

Sorry you can´t read swedish - I could link you to 10 - 15 years old post there I combat cyanobacteria with help of NO3 additives. This was the time when cyanobacteria was seen as a result of high nutrients values. after some years - it was accepted - at least here in Sweden that it was a low nutrient problem in around 80 - 90 % of the cases. In this cases I work with - it was mostly Oscillatoria - red and green mats. There is - however other forms of cyanobacteria - often mistaken for dinoflagellates if you only look at them in aquarium - IMO - like Lyngbya majuscula

The first reports of massive cyanobacteria outbreak was coming when the ULS system become popular in Europe and more and more reefers connected this with low nutrients systems. Even low P could trigger outbreaks.

I admit that it is a lot of misidentifying that have happens - there is mats that looks like cyanobacteria mats but if you look at them in a microscope - you will find a lot of dinoflagellates inside the mats too. These mats is not a mat of cells - it is a lot of cells pulled together of mostly different hydrocarbons as I understand it. I will see this as a external storage of overflow energy from the photosynthesis. Its pure energy and for these dinoflagellates that is a combination of autotrophic and heterotrophic organism - it is the Swedish smorgasbord. It is not surprising that you will see a mixed fauna inside these mats. Both Oscillatoria and lyngbya can be seen as small "sticks" but it seems like Oscillatoria and sometimes spirulina will form mats and lyngbya this long threads that can be mistaken for dinoflagellates IMO.

But both organism will be favoured by low nutrient concentration (or triggered to form mats (Cyanobacteria)) by low nutrient concentration. According to NO3 role in this in this case (whats happens below the mats) - my opinion is that its in not only a nutrient question (NO3-N) - it is the whole molecules ability to hinder or slow down hydrogen sulfide formation below the mats that makes a difference.

Sincerely Lasse

 

[sixty_reefer]

Its a ratio of 38:1 as NO3-N : P - not so bad as a ratio and I think that your aquarium work well @Thales. In my aquarium - i have a ratio between NO3-N and other N -species of 1:1 - Seen as total N : P - you may be around 80 : 1. Triton have 147 : 1 as their target value as total N : total P. I have lower total concentration - nearly a tenfold lower - but my ratio is nearly the same as yours.


Sorry you can´t read swedish - I could link you to 10 - 15 years old post there I combat cyanobacteria with help of NO3 additives. This was the time when cyanobacteria was seen as a result of high nutrients values. after some years - it was accepted - at least here in Sweden that it was a low nutrient problem in around 80 - 90 % of the cases. In this cases I work with - it was mostly Oscillatoria - red and green mats. There is - however other forms of cyanobacteria - often mistaken for dinoflagellates if you only look at them in aquarium - IMO - like Lyngbya majuscula

The first reports of massive cyanobacteria outbreak was coming when the ULS system become popular in Europe and more and more reefers connected this with low nutrients systems. Even low P could trigger outbreaks.

I admit that it is a lot of misidentifying that have happens - there is mats that looks like cyanobacteria mats but if you look at them in a microscope - you will find a lot of dinoflagellates inside the mats too. These mats is not a mat of cells - it is a lot of cells pulled together of mostly different hydrocarbons as I understand it. I will see this as a external storage of overflow energy from the photosynthesis. Its pure energy and for these dinoflagellates that is a combination of autotrophic and heterotrophic organism - it is the Swedish smorgasbord. It is not surprising that you will see a mixed fauna inside these mats. Both Oscillatoria and lyngbya can be seen as small "sticks" but it seems like Oscillatoria and sometimes spirulina will form mats and lyngbya this long threads that can be mistaken for dinoflagellates IMO.

But both organism will be favoured by low nutrient concentration (or triggered to form mats (Cyanobacteria)) by low nutrient concentration. According to NO3 role in this in this case (whats happens below the mats) - my opinion is that its in not only a nutrient question (NO3-N) - it is the whole molecules ability to hinder or slow down hydrogen sulfide formation below the mats that makes a difference.

Sincerely Lasse

Can I ask you how did you got 38 No3-N Lasse? Isn’t No3 = no3-N * 4.427 ? And am I correct in thinking that 1ppb phosphorus = 0.003 ppm phosphate

Unfortunately I can’t reed Swedish but will see if I can find any papers translated

 

[sixty_reefer]

According to my calculations a 50 no3 and 0.91 phosphate translate to 3422:1 nitrogen phosphorus ratio, am I wrong in thinking that @Lasse

 

[Lasse]

Is nitrate of 50 and phosphate of .91 a big imbalance?

My bold and Nitrate is NO3, Phosphate is PO4

I do not know where you get ppb from - I read @Thales post as it is ppm both values and I do my calculation like this

NO3 molar weight is 14 +3*16 = 62. NO3-N will be 14/62 = 0,225 = 22,5 %
50 ppm NO3 will be 50 * 0.225 = 11.25 ppm as NO3-N
PO4 molar weight is 31+4*16 = 95 P will be 31/95 = 0.326 = 32,6 %
0,91 ppm PO4 will be 0.91*0.326 = 0.296 ppm as PO4-P

11,25/0.296 = 38 N/P ratio

According to my calculations a 50 no3 and 0.91 phosphate translate to 3422:1 nitrogen phosphorus ratio, am I wrong in thinking that @Lasse

Yes if @Thales meant ppm in his post - your wrong. and only he can thale if its wrong assumption of me or not


Sincerely Lasse

 

[sixty_reefer]

My bold and Nitrate is NO3, Phosphate is PO4

I do not know where you get ppb from - I read @Thales post as it is ppm both values and I do my calculation like this

NO3 molar weight is 14 +3*16 = 62. NO3-N will be 14/62 = 0,225 = 22,5 %
50 ppm NO3 will be 50 * 0.225 = 11.25 ppm as NO3-N
PO4 molar weight is 31+4*16 = 95 P will be 31/95 = 0.326 = 32,6 %
0,91 ppm PO4 will be 0.91*0.326 = 0.296 ppm as PO4-P

11,25/0.296 = 38 N/P ratio



Yes if @Thales meant ppm in his post - your wrong. and only he can thale if its wrong assumption of me or not


Sincerely Lasse

In my calculations I had the similar no3-N at 11.29ppm and you got 11.25ppm

I think the difference is in po4 as redfield is in phosphorus not in phosphates did you converted Po4 to P?

In my conversion i got 303ppb phosphorus

 

[Thales]

NO3- (because that is the metric the hobby mostly uses. PO43- for the same reason. mg/l or ppm (they are the same)

 

[Lasse]

In my calculations I had the similar no3-N at 11.29ppm and you got 11.25ppm

I think the difference is in po4 as redfield is in phosphorus not in phosphates did you converted Po4 to P?

In my conversion i got 303ppb phosphorus

My calculated ratio is NO3-N (ppm) divided with PO4-P (ppm) You can´t use one sort for the numerator and another for the denominator. You can´t divide 11.25 (or 11.29 if you use all decimals) ppm N with 296 ppb P because 296 ppb is 0.296 ppm

Sincerely Lasse

 

[sixty_reefer]

My calculated ratio is NO3-N (ppm) divided with PO4-P (ppm) You can´t use one sort for the numerator and another for the denominator. You can´t divide 11.25 (or 11.29 if you use all decimals) ppm N with 296 ppb P because 296 ppb is 0.296 ppm


Sincerely Lasse

Thanks @Lasse got it now

 

[Cory]

I think its more important to consider what an animals needs are for no3 and po4 and maintain that accordingly so one doest become limiting instead of targeting the redfield ratio for phytoplankton.

 

[BAUCE]

someone want to do the math for me so that I can have the best aquarium ever created? my phosphates are .08 . What would the ideal nitrate be?

 

[Cory]

someone want to do the math for me so that I can have the best aquarium ever created? my phosphates are .08 . What would the ideal nitrate be?

Depends how many organisms you have consuming it or how fast it goes down. Lol

 

[Cory]

Smith has already verified in his studies that the N : P ratio below 29 favored the proliferation of cyanobacteria, which were more efficient in fixing N (11, 12).

What do they mean ratio below 29? 29 what? Whats the ratio cyano favor?

 

[Cory]

As dinoflagellates is the species tha thrive under low nutrients and it’s normally under control by increasing no3 and po4

In my experience very high no3 and low to no po4 has caused osteo dinos in my tank. Ive also found scientific articles saying more than usual N is usually associated with dino blooms.

 

[Cory]

I think its more important to consider what an animals needs are for no3 and po4 and maintain that accordingly so one growth factor doesn't become limiting instead of targeting the redfield ratio for phytoplankton which is what phytoplankton need for growth, not all species in a coral reef. Im sure that all species are happy with some of both. But selecting a ratio is based on what is there.

Its clear nature has organisms that become abundant because as your article explains help them to become the dominant species for that moment in time that their unique biology has evolved to overcome any deficiencies or not having a competitive advantage. Some species are just better or worse at getting their energy requirements and thus we have survival or succumbing based on environmental conditions, fluxes and upwellings, season patterns, dust from deserts bringing iron.

It is best then to choose a target level and maintain it. But how much is the question.

 

[Futuretotm]

here are the "MASTERS" of reefing average numbers:

Alk was 8.19, Ca 419. Mg 1361, NO3 18.77, PO4 .18, Sr 8.6 and temp 77

Masters included are:
Julian Sprung of Two Little Fishes NO3 10-15, PO4 .015
front tank WWC NO3 10-15, PO4 .03-,08
Julian and Cruz of Elegant Corals NO3 5, PO4 .05
Stuart Bertram NO3 15-20, PO4 .046
Jeff Leung NO3 54, PO4 .04
Brad Syphus NO3 20, PO4 .10-.20
Jason Fox NO3 5-10, PO4 .08-.10
Dr. Sanjay No3 20-40, PO4 .12-.22

All credit to @Mike Paletta and this orignal thread at: https://www.reef2reef.com/threads/tank-parameters-of-some-masters.295215/