Anyone moved to low nitrate higher phosphate method?

[jonone]

Hi I have just set up a 25g nano it’s been running approx 4 months, recently I bottomed out my phosphates and noticed my chalice corals starting to “bleach” so I’m dosing some neophos.
At the minute my nitrates are 6.6ppm and my phosphates are 0.02ppm
This lead me to research the subject and came across a few threads suggesting nitrate is not very important and can be seen as more of a waste product.
Some people seems to suggest corals need very little nitrate but algae needs higher amounts
They also suggest higher levels of phosphate to a point are better for coral growth and don’t stimulate algae growth if nitrates are kept low.
I was wondering if anyone has moved over to this method and having “ better “ success ?
I’m aware you can run a tank either way but has anyone compared the two methods ?
What’s the ideal levels for you and what would you recommend as a typical range for best success ?
Thoughts on Cyano related to nutrient balance would greatly be appreciated ? Does this even matter for cyano ?

 

[Pod_01]

Not sure about moving over to the method, but my tank tends to run like this:

Some corals:

I tend to let the tank do its thing and I only try to interfere when corals are not looking good. Otherwise I just monitor how things develop.
Corals do require both PO4 and N, fish provides ammonia great source of N.

Good luck,

 

[jackson6745]

Understand that these number are not exactly a method, but the end result. There are very different metabolic processes involved that can give you the same numbers. A first hand example, I had a tank years ago that I ran as an experiment with no fish or feeding. Nitrates and phosphate were undetectable or registered low. Corals were pale with little polyp extension, some died. I had the same nitrate and phosphate readings on different system with lots of fish and feeding, yet my colors were rich and coral heath was/is spectacular.

 

[jonone]

Not sure about moving over to the method, but my tank tends to run like this:

Some corals:

I tend to let the tank do its thing and I only try to interfere when corals are not looking good. Otherwise I just monitor how things develop.
Corals do require both PO4 and N, fish provides ammonia great source of N.

Good luck,

Looks beautiful and very successful , your numbers would fall into that approach even if unintentional I guess

 

[jonone]

Understand that these number are not exactly a method, but the end result. There are very different metabolic processes involved that can give you the same numbers. A first hand example, I had a tank years ago that I ran as an experiment with no fish or feeding. Nitrates and phosphate were undetectable or registered low. Corals were pale with little polyp extension, some died. I had the same nitrate and phosphate readings on different system with lots of fish and feeding, yet my colors were rich and coral heath was/is spectacular.

Well I say “method “ but maybe that’s the wrong word
But if your intentionally keeping nitrates low say via carbon dosing and keeping phosphates pinned at .1 I’m not really sure what to call it ?
Obviously if your nutrients just fall into that area it’s not a method

 

[Freenow54]

Not sure about moving over to the method, but my tank tends to run like this:

Some corals:

I tend to let the tank do its thing and I only try to interfere when corals are not looking good. Otherwise I just monitor how things develop.
Corals do require both PO4 and N, fish provides ammonia great source of N.

Good luck,

Could you please explain the 2 Phosphate readings?

 

[jonone]

Another question I’d like to ask is if I raise my phosphates by dosing will nitrates naturally fall?
Or are they independent in that regard ?

Also if I want to raise phosphates to say 0.1ppm is it better to lower my nitrates first so I’m not in the middle ground for both nutrients incase of fueling algae etc
Thanks

 

[Randy Holmes-Farley Verified Community Expert]

Hi I have just set up a 25g nano it’s been running approx 4 months, recently I bottomed out my phosphates and noticed my chalice corals starting to “bleach” so I’m dosing some neophos.
At the minute my nitrates are 6.6ppm and my phosphates are 0.02ppm
This lead me to research the subject and came across a few threads suggesting nitrate is not very important and can be seen as more of a waste product.
Some people seems to suggest corals need very little nitrate but algae needs higher amounts
They also suggest higher levels of phosphate to a point are better for coral growth and don’t stimulate algae growth if nitrates are kept low.
I was wondering if anyone has moved over to this method and having “ better “ success ?
I’m aware you can run a tank either way but has anyone compared the two methods ?
What’s the ideal levels for you and what would you recommend as a typical range for best success ?
Thoughts on Cyano related to nutrient balance would greatly be appreciated ? Does this even matter for cyano ?

Nitrate is not a waste product any more than phosphate is, but either can be substituted by other N and P compounds if those are sufficiently available.

This is my recommendation:

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/
4. What targets seem reasonable? Of course, that depends on all the other factors at play, such as types of corals, availability of ammonia, particulate foods, etc. However, for a mature mixed reef, this would be how I personally would run it:

• Let nitrate float between 5 ppm and 50 ppm. I’d use gentle export in this range, such as growing macroalgae.
• Above 50 ppm, I’d begin to focus more on reducing it, by organic carbon dosing, turf or macroalgae, etc.
• Below 5 ppm, I’d begin to dose ammonia or feed more. The target level might drop lower if dosing ammonia, just like the heavy in/heavy out scenario where nitrate may not be as needed.
• Let phosphate float between about 0.06 ppm and 0.3 ppm. This range is higher than I’ve recommended in the past. I’d use gentle export in this range, such as growing macroalgae.
• Above about 0.3 ppm, I’d begin to focus more on reducing it, by turf or macroalgae, or a binder such as GFO or lanthanum (has its own risks to tangs). If a binder: GO SLOW. Turf and macroalgae will typically be slow enough.
• Below 0.06 ppm, I’d begin to dose sodium phosphate or feed more to get the level up.

 

[Luminous74]

I have spent a lot of time in the past dealing with the topic of nutrients in reef aquariums and have tried various strategies. I followed different recommendations – from low nitrate and phosphate levels to alternatives like ammonium instead of nitrate.

Whenever I intervened too strongly, especially when values were too low (NO₃ < 1 mg/l, PO₄ < 0.05 mg/l), my animals reacted negatively. They showed poor health, and at the same time, cyanobacteria or filamentous algae experienced a growth surge. Once the levels were slightly higher, I had significantly fewer problems – no cyano or filamentous algae.

I have had nitrate levels as high as 25 mg/l and phosphate up to 0.2 mg/l, and under these conditions, coral growth and coloration were generally better. My experience has shown me that the animals themselves indicate what is best for them. There are no universal guidelines, as every tank is unique. This also means that not every coral will thrive under the specific conditions in a given system.

Randy Holmes-Farley’s recommendations fit my tank very well and have helped me establish a stable nutrient strategy.

 

[jonone]

Nitrate is not a waste product any more than phosphate is, but either can be substituted by other N and P compounds if those are sufficiently available.

This is my recommendation:

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/
4. What targets seem reasonable? Of course, that depends on all the other factors at play, such as types of corals, availability of ammonia, particulate foods, etc. However, for a mature mixed reef, this would be how I personally would run it:

• Let nitrate float between 5 ppm and 50 ppm. I’d use gentle export in this range, such as growing macroalgae.
• Above 50 ppm, I’d begin to focus more on reducing it, by organic carbon dosing, turf or macroalgae, etc.
• Below 5 ppm, I’d begin to dose ammonia or feed more. The target level might drop lower if dosing ammonia, just like the heavy in/heavy out scenario where nitrate may not be as needed.
• Let phosphate float between about 0.06 ppm and 0.3 ppm. This range is higher than I’ve recommended in the past. I’d use gentle export in this range, such as growing macroalgae.
• Above about 0.3 ppm, I’d begin to focus more on reducing it, by turf or macroalgae, or a binder such as GFO or lanthanum (has its own risks to tangs). If a binder: GO SLOW. Turf and macroalgae will typically be slow enough.
• Below 0.06 ppm, I’d begin to dose sodium phosphate or feed more to get the level up.

Thanks for the input
I’m a beginner and not educated in chemistry so please take this as questions not statements

The nitrate as a waste product is from hans Werner
I guess this is because it’s the end of the nitrogen cycle and what corals really want it ammonium ? So he is suggesting nitrate in itself is not needed?
I’ve heard another member suggest that if your nitrates are high then it’s a measure of putting to much ammonium (food ) into the system
I also have seen another member comment that the idea of reduced nitrates is so the zooxanthelle receives the sugars from the coral not via the water column.

I’m sure the numbers you suggest are very much in line for a successful reef tank but I guess I’m trying to narrow down the optimum or a better set of parameters if possible…..

 

[jonone]

I have spent a lot of time in the past dealing with the topic of nutrients in reef aquariums and have tried various strategies. I followed different recommendations – from low nitrate and phosphate levels to alternatives like ammonium instead of nitrate.

Whenever I intervened too strongly, especially when values were too low (NO₃ < 1 mg/l, PO₄ < 0.05 mg/l), my animals reacted negatively. They showed poor health, and at the same time, cyanobacteria or filamentous algae experienced a growth surge. Once the levels were slightly higher, I had significantly fewer problems – no cyano or filamentous algae.

I have had nitrate levels as high as 25 mg/l and phosphate up to 0.2 mg/l, and under these conditions, coral growth and coloration were generally better. My experience has shown me that the animals themselves indicate what is best for them. There are no universal guidelines, as every tank is unique. This also means that not every coral will thrive under the specific conditions in a given system.

Randy Holmes-Farley’s recommendations fit my tank very well and have helped me establish a stable nutrient strategy.

Well I have definitely seen the effect of dropping phosphates to fast I got rtn on Montipora after using rowa phos and now bleaching on my chalice corals
I will refrain from using rowaphos again that’s for sure
I’m pretty sure I can keep my levels well with randy’s recommendations with water changes and feeding within my nano ( no skimmer )

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for the input
I’m a beginner and not educated in chemistry so please take this as questions not statements

The nitrate as a waste product is from hans Werner
I guess this is because it’s the end of the nitrogen cycle and what corals really want it ammonium ? So he is suggesting nitrate in itself is not needed?
I’ve heard another member suggest that if your nitrates are high then it’s a measure of putting to much ammonium (food ) into the system
I also have seen another member comment that the idea of reduced nitrates is so the zooxanthelle receives the sugars from the coral not via the water column.

I’m sure the numbers you suggest are very much in line for a successful reef tank but I guess I’m trying to narrow down the optimum or a better set of parameters if possible…..

Corals prefer ammonia to nitrate when given both. But they can consume nitrate just fine. I prefer ice cream to
kale, but that does not make kale a waste product.

Elevated nitrate just means more N added in foods than is consumed by organisms. It doesn’t mean the feeding is too much for the organisms consuming it.

The sugar thing presumably implies the zoox are growing too much and not sending as much sugar to the coral body. I don’t know if there’s evidence that happens and/or is a problem.

Did you read through the article? It shows examples of great tanks at widely divergent nitrate and phosphate levels. Thus, it is impossible to narrow the recommendation in general, but any specific tank may have its own sweet spot for the reasons given in the article.

 

[Luminous74]

I guess this is because it’s the end of the nitrogen cycle and what corals really want it ammonium ? So he is suggesting nitrate in itself is not needed?
I’ve heard another member suggest that if your nitrates are high then it’s a measure of putting to much ammonium (food ) into the system
I also have seen another member comment that the idea of reduced nitrates is so the zooxanthelle receives the sugars from the coral not via the water column.

I am following your questions with great interest and would like to share some thoughts:

Corals and their zooxanthellae require nitrogen (N) for their growth. It is now believed that they prefer reduced nitrogen compounds, particularly ammonium. In a functioning system, ammonium is oxidized to nitrite and then to nitrate.

If nitrate accumulates in the water, this suggests that there is an excess of nitrogen in the system. At the same time, in a properly functioning nitrogen cycle, ammonium should always be present and continuously oxidized to nitrate. But how can I be sure that, in the absence of detectable nitrate, there is still enough nitrogen available in the system? Can only the animals indicate this?

My conclusion from this is that it is better to have a measurable nitrate level that I can monitor and react to when it rises or falls. There is also the idea that while we can add substances to the system, we cannot fully control who consumes them—whether bacteria, algae, or corals.

This leads to the key question: In a system where nitrate is not detectable, is there truly enough nitrogen available to prevent limitation?

Another aspect that I find unclear: Sometimes, in aquariums with stable nitrate levels, the addition of ammonium causes the PO₄ level to drop. What is the reason for this? Is ammonium limited in such a system, or is it being oxidized to nitrate too quickly, so that the additional ammonium dosing stimulates the growth of previously limited organisms, which then consume additional PO₄?

 

[Pod_01]

Not the expert but here it goes:
P - is phosphate as element that is measured by ICP in the water sample, all of the types of P.

PO4(total) - Is total PO4 calculated based on the P.

PO4 (photometric) - is Ortho- phosphate or phosphate that is measured by most test kits.

Difference between total and ortho phosphate shows that there are other sources of PO4 in the reef tank that can be used by corals.

 

[Luminous74]

Difference between total and ortho phosphate shows that there are other sources of PO4 in the reef tank that can be used by corals.

I am also not a chemistry expert, but it was explained to me in a similar way to how you describe it. What I would like to add: The ICP analysis measures the total PO₄ value. However, the problem is that this does not directly indicate whether all of it is actually available to the corals. Orthophosphate should generally be available to corals, while for the remaining phosphate compounds, we do not know exactly in what form they exist and whether corals can utilize them.

I was also told that the PO₄ value from the ICP analysis should be equal to or higher than the value we measure with our standard home tests due to the measurement method. If it is much lower, there is either a measurement error or an impure sample.

From my understanding, PO₄ is more difficult to manage than NO₃. If NO₃ is detected, it is present—assuming measurement errors are ruled out. PO₄, on the other hand, reacts with various substances, can precipitate, and in certain systems, it can be very difficult to maintain it in the available orthophosphate form without having to dose an unreasonably large amount.

 

[Randy Holmes-Farley Verified Community Expert]

Difference between total and ortho phosphate shows that there are other sources of PO4 in the reef tank that can be used by corals.

I’d qualify that last phrase to read

that may or may not be usable by corals.

 

[Freenow54]

I was informed you don't accept Direct Messaging. I just wanted to tell you that I followed your advice, and installed a UV light in series with my RO system. I ran new 1/4 inch lines from about 40 feet away from the unit. Both cold, and hot. So the UV is that far away from the hot line and has to travel through the 1/2 pipe all the way back to the water heater. This was actually recommended by the manufacturer and of course I did not do it. It was time and money well spent, and notice a difference which is scary when you think about it the odor I had in the hot water is gone. I attributed it to the sacrificial anode doing its job. Wrong again. So Thank you for your patience

 

[jonone]

I am following your questions with great interest and would like to share some thoughts:

Corals and their zooxanthellae require nitrogen (N) for their growth. It is now believed that they prefer reduced nitrogen compounds, particularly ammonium. In a functioning system, ammonium is oxidized to nitrite and then to nitrate.

If nitrate accumulates in the water, this suggests that there is an excess of nitrogen in the system. At the same time, in a properly functioning nitrogen cycle, ammonium should always be present and continuously oxidized to nitrate. But how can I be sure that, in the absence of detectable nitrate, there is still enough nitrogen available in the system? Can only the animals indicate this?

My conclusion from this is that it is better to have a measurable nitrate level that I can monitor and react to when it rises or falls. There is also the idea that while we can add substances to the system, we cannot fully control who consumes them—whether bacteria, algae, or corals.

This leads to the key question: In a system where nitrate is not detectable, is there truly enough nitrogen available to prevent limitation?

Another aspect that I find unclear: Sometimes, in aquariums with stable nitrate levels, the addition of ammonium causes the PO₄ level to drop. What is the reason for this? Is ammonium limited in such a system, or is it being oxidized to nitrate too quickly, so that the additional ammonium dosing stimulates the growth of previously limited organisms, which then consume additional PO₄?

There has never been a mention of non detectable nitrate just very low levels to stop algae growing when the phosphates are slightly
And to stop the zoox receiving the nitrates from the water column

I guess one question is where does the trend for “low phosphates “ high nitrates come from ? My guess is to help stop algae growth
Where it seems algae needs / wants nitrate more then phosphate ?

 

[Randy Holmes-Farley Verified Community Expert]

I was informed you don't accept Direct Messaging. I just wanted to tell you that I followed your advice, and installed a UV light in series with my RO system. I ran new 1/4 inch lines from about 40 feet away from the unit. Both cold, and hot. So the UV is that far away from the hot line and has to travel through the 1/2 pipe all the way back to the water heater. This was actually recommended by the manufacturer and of course I did not do it. It was time and money well spent, and notice a difference which is scary when you think about it the odor I had in the hot water is gone. I attributed it to the sacrificial anode doing its job. Wrong again. So Thank you for your patience

You're welcome.

Happy reefing. :)

 

[Randy Holmes-Farley Verified Community Expert]

I guess one question is where does the trend for “low phosphates “ high nitrates come from ? My guess is to help stop algae growth
Where it seems algae needs / wants nitrate more then phosphate ?

Not sure I'm seeing such a trend in intended target levels. It may come about in many tanks without that being specifically intended, especially those with newish dead rock and/or sand which can bind and lower phosphate.

Do you see someone posting a recommendation for low phosphate (say, below 0.03 ppm) and high nitrate (say, above 30 ppm)?