Could we utilise the Redfield ratio a little better in aquaria?

[Miami Reef]

if a reef tank is limited by P for example that we cannot lower nitrates using organic carbon due to the bacteria becoming limited in one nutrient

So just increase the limiting nutrient? Why do you need to put it in a ratio? That’s pointless.

 

[ReneReef]

It’s debatable...

No, I don't think so.

...if we were discussing method to lower phosphate using the bacteria it would become relevant or increasing bacteria to feed coral and filter feeders.

Knowing on average that for every 0.01 ppm of phosphates exported from the system will need on average 0.16 ppm to 0.25 ppm of Nitrates available in the water column.

I’m a system with 0.8 ppm phosphate and 1ppm nitrate we could theoretically calculate how much Nitrate would have need to add to the system to reduce 0.8 ppm phosphate to 0.05 ppm phosphate for example.

You are vastly oversimplifying again.
- What Miami Reef said.
- Do those bacteria actually prefer nitrate or do they want something else?
- Are you target feeding that nitrate to those bacteria?
- Is this in any way a convenient way to lower phosphate?
- Also, now you're assuming N equals N from Nitrate again, while earlier you said that was not wat you meant...
- A ratio of 16:1 N to P is in number of atoms, that does not equal 16:1 ppm nitrate and phosphate.

Again, even if, no it won't, but if that ratio turned out the way in your example. There's no need to know it.

In the situation you present, I would dose ammonia to make sure N stays available and increase the growth of my corals (increased coral growth -> increase PO4 uptake) and I'd use lanthanum or some phosphate absorber to effectively and easily reduce phosphate.

Why have bacteria grow, when you can have more coral???

 

[areefer01]

One problem here could be that a prominent hobbyist continues to mention the ratio and attributes to their success. Or success of the aquariums they find attractive in their sample study.

Moth to a flame after that even though actual chemist try to educate otherwise.

 

[sixty_reefer]

they would be better served just sticking to a range of values and avoiding bottoming out like has been advocated for decades now.

Advocated but not a rule, to date I’ve not seen a reasonable reason given by anyone on why not bottoming out certain nutrients.

you may get dinoflagellates it’s not a answer to the question imo.

 

[sixty_reefer]

i feel like you're overdoing it. sure if enough information on factors are known you can predict with reasonable accuracy what will happen in x amount of time but whats the point?

I feel that being a few steps ahead on what will happen helps with preparation.

you say a certain bacteria will remove a certain amount of nitrate and in a certain rate a certain amount of phosphate, but you don't have only that one type of bacteria in your tank now do you? so I really don't see the point you are trying to make. just make sure nether your nitrates nor your phosphates bottom out or rise drastically and your tank will be perfectly fine

According to DNA testing in reef aquaria it has been confirmed that heterotrophic bacteria is the main strain of bacteria in a mature system.
I believe that knowing their nutritional needs can only be beneficial.

 

[sixty_reefer]

No, I don't think so.


You are vastly oversimplifying again.
- What Miami Reef said.
- Do those bacteria actually prefer nitrate or do they want something else?
- Are you target feeding that nitrate to those bacteria?
- Is this in any way a convenient way to lower phosphate?
- Also, now you're assuming N equals N from Nitrate again, while earlier you said that was not wat you meant...
- A ratio of 16:1 N to P is in number of atoms, that does not equal 16:1 ppm nitrate and phosphate.

Again, even if, no it won't, but if that ratio turned out the way in your example. There's no need to know it.

In the situation you present, I would dose ammonia to make sure N stays available and increase the growth of my corals (increased coral growth -> increase PO4 uptake) and I'd use lanthanum or some phosphate absorber to effectively and easily reduce phosphate.

Why have bacteria grow, when you can have more coral???

Heterotrophic bacteria has a preference for nitrate they to my knowledge are the most effective organisms at transforming inorganic nutrients into organic nutrients therefore a good organism to remove pollutants like nitrates and phosphate from aquaria.

I believe I mentioned in the beginning of the thread that it was a nitrate to phosphate ratio if I didn’t I do apologise.
In some testing before with phytoplankton as a organic carbon source I did got a ratio of 24:1 nitrate to phosphate although the nutrients in the phytoplankton culture could have messed slightly with the ratio of assimilation.

 

[BeanAnimal]

What does that have to do with the Redfield Ratio though?

You are trying to make the distinction between what is being consumed, vs what is available. I am not sure what the point of that is.

If you need a certain ratio of fat, carbs, and protein to be healthy, that is a ratio. If we remove one or more of those from your diet, that does not change the "ratio" that is needed. It just means you don't have what you need. At the same time if we send you to a buffet that has 10x more of everything than you need, that also does not change the ratio of what you need.

You said your contention is not to adjust the levels of N and P with respect to each other... okay, then the bacteria pick and choose what they want as long as there is enough... so what is the point of discussing the ratio?

 

[sixty_reefer]

So just increase the limiting nutrient? Why do you need to put it in a ratio? That’s pointless.

That’s a fair point although nitrates for example are not a limiting nutrient for coral.

 

[Hats_]

I feel that being a few steps ahead on what will happen helps with preparation.



According to DNA testing in reef aquaria it has been confirmed that heterotrophic bacteria is the main strain of bacteria in a mature system.
I believe that knowing their nutritional needs can only be beneficial.

this still doesn't make a point why a ratio is a necessity? they have to just be there in order to be consumed, also nitrate is the final strain in the process and the most difficult to metabolise so why is nitrate important at all, the bacteria probably feed on ammonia and nitrite before it even becomes measurable to you as a reefer

 

[sixty_reefer]

What does that have to do with the Redfield Ratio though?

You are trying to make the distinction between what is being consumed, vs what is available. I am not sure what the point of that is.

If you need a certain ratio of fat, carbs, and protein to be healthy, that is a ratio. If we remove one or more of those from your diet, that does not change the "ratio" that is needed. It just means you don't have what you need. At the same time if we send you to a buffet that has 10x more of everything than you need, that also does not change the ratio of what you need.

You said your contention is not to adjust the levels of N and P with respect to each other... okay, then the bacteria pick and choose what they want as long as there is enough... so what is the point of discussing the ratio?

The Redfield ratio is the study of nutrient limitation, in this thread I was hoping to discuss the ratio in heterotrophic bacteria Not phytoplankton.

Different organisms with similar needs we are also heterotrophic.

 

[Hats_]

The Redfield ratio is the study of nutrient limitation, in this thread I was hoping to discuss the ratio in heterotrophic bacteria Not phytoplankton.

Different organisms with similar needs we are also heterotrophic.

does every heterotrophic bacteria have the same nutritional needs? i don't assume so?

 

[sixty_reefer]

this still doesn't make a point why a ratio is a necessity? they have to just be there in order to be consumed, also nitrate is the final strain in the process and the most difficult to metabolise so why is nitrate important at all, the bacteria probably feed on ammonia and nitrite before it even becomes measurable to you as a reefer

It brings knowledge, for example going back to heterotrophic bacteria in aquaria they help define most of the residual nitrate and phosphate by a limitation in DOC available in the water column. In other words the current residual nitrate and phosphate in a system finds its equilibrium/balance via the carbohydrate that is produced by fish waste and other products we may add to it.

 

[sixty_reefer]

does every heterotrophic bacteria have the same nutritional needs? i don't assume so?

From what I read, most of the pelagic heterotrophic bacteria have similar needs.

 

[Formulator]

 

[BeanAnimal]

The Redfield ratio is the study of nutrient limitation, in this thread I was hoping to discuss the ratio in heterotrophic bacteria Not phytoplankton.

Different organisms with similar needs we are also heterotrophic.

I understand the Redfield Ratio. The point remains made in the analogy, whether for bacteria or phytoplankton, nutrient limitation occurs when either N or P is depleted. As long as neither hits zero, their growth continues.

 

[sixty_reefer]

I understand the Redfield Ratio. The point remains made in the analogy, whether for bacteria or phytoplankton, nutrient limitation occurs when either N or P is depleted. As long as neither hits zero, their growth continues.

This is a valid point, it’s easy to keep Nitrate and phosphate detectable although in the hobby we can’t test for DOC easily at home not knowing if the bacteria has become limited in C.

My thought is that if everything is going fine in an aquarium and Nitrates and Phosphate are stable we could have an indication that all organisms are getting the CNP that they need.

In other cases were residual deviate from ideal residual a C limitation can be identified by seeing a constant rise in Nitrate and Phosphate. This determination can only be identified at home by using the study of nutrient limitation in my view.

 

[hart24601]

Advocated but not a rule, to date I’ve not seen a reasonable reason given by anyone on why not bottoming out certain nutrients.

you may get dinoflagellates it’s not a answer to the question imo.

How about the reason coral need nutrients to grow?

 

[sixty_reefer]

Man listen to me....

Forget...

I almost went crazy at the lightness day and night on the redfield. Pure madness.. Every time you get cyan all that **** they'll tell you about redfield (you put them on the ignore list)

No3 between 2-10 ppm
Po4 0.03 max 0.1...

I've read to many post, thread on Redfield here, reefcentral.com ecc..I've read so much in a crazy way.

Completely no sense ratio...

Food for fish, one food (i advise sps evo easy reef) for corals, water change weekly or 10,15 days.. Stop..

I understand your view, with so many using the phytoplankton ratio to try and set a residual ratio that has no benefit.
This discussion is not on that, Redfield is used to interpret nutrient limitations, setting a parameter/residual to a system it’s a personal choice and not applicable to this discussion imo

 

[sixty_reefer]

How about the reason coral need nutrients to grow?

Several experts will tell you that they will prefer more basic forms of nitrogen over Nitrate, there’s a good link to a thread on the first page we’re a fairly knowledgeable chap from tropic marine elaborates on it.

Edit:
To correct my earlier question, to date I haven’t seen an answer to why not bottom out Nitrate. Just a advice although no back up information or explanation

 

[Randy Holmes-Farley]

Advocated but not a rule, to date I’ve not seen a reasonable reason given by anyone on why not bottoming out certain nutrients.

you may get dinoflagellates it’s not a answer to the question imo.

What’s the uncertainty in this context?

There are theories about how nutrients too low can limit growth or organisms that compete with dinos for space. Its not been proven but it fits many experiences.