High Nitrate - Low Phosphate

[Comic_Reef]

Great discussion/ info. Find myself in this predicament now. Zero PO4, Zero cyano, zero macro, zero GFO in system for months, few corals were looking “off” have been checking, checking, and checking some more. Got a new PO4 kit (Salifert) and consistently getting 0 PO4 as I was with prior kit, and somewhere btwn 50-100 on N03 color scale. I have increased feeding a little and let the cubes melt in a net sitting in the sump hoping that would help the PO4 but to no success after 2 weeks. I have ordered NeoPhos, which should be here today, to try dosing some PO4 as mentioned prior in the thread.

One product I see recommended a lot when people suspect metals, or have confined metals by ICP, is PolyFilter. PolyFilter will remove some metal however it removes all forms of phosphate at a much faster rate. Found this out the hard way after I applied the PolyFilter for elevated zinc and iron, the corals were not responding well and I was still blaming metals for the decline in health. After searching for more info I found that the PolyFilter is profoundly good at PO4 reduction versus metals absorption. Several high end colonies later I find that zero PO4 was likely the culprit the entire time.

Thanks for the Redfield Ratio info and the info from your personal experience with this matter.

Just make sure to approach this slowly. You should see your dosed phosphates disappear quickly, I mean within a day. It'll get frustrating because even after dosing you won't be able to keep a detectable level but stay at it and you should begin to see the NO3 take a sudden downturn assuming you have a good bacteria load and filtration. Get ready for the uglies after things begin to rebalance its totally normal and will last a few months.

 

[Cory]

I agree.

Most people read that reefs are nutrient poor. The truth is they get upwelling of nutrients that feed the reef.

 

[Timfish]

Glad you posted your experiences! Sadly the notion PO4 has to be kept low got ingrained in the reefer dogma in spite of the observations and comments of researchers who study reefs. J. E. N. Veron made this observation over 3 decades "Imported nutrients are usually transported to reefs from rivers; but if there are no rivers, as with reefs remote from land masses, nutrients can only come from surface ocean circulation. Often this supply is poor, and thus the vast ocean expanses have been refered to as "nutrient deserts". The Indo-Pacific has many huge atolls in these supposed deserts which testify to the resilience of reefs, but the corals themselves may lack the lush appearance of those of more fertile waters. Many reefs have another major supply of inorganic nutrients as, under certain conditions, surface currents moving against a reef face may cause deep ocean water to be drawn to the surface. This "upwelled" water is often rich in phosphorus and other essential chemicals." J. E. N. Veron "Corals of Austrailia and the Indo-Pacific" pg 30. Charles Delbeek wrote this observation and warning almost a decade ago "When I see the colors of some of these low nutrient tanks, I can't help but be reminded of bleached coral reefs. It should therefore not come as a surprise that feeding corals in such systems becomes a very important component in these systems. Though reefs are often catagorized as nutrient "deserts" the influx of nutrients in the form of particulates and plankton is quite high when the total volume of water passing over a reef is taken into consideration.

Our crystal-clear aquaria do not come close to the nutrient loads that swirl around natural reefs. And so when we create low-nutrient water conditions, we still have to deal with the rest of a much more complex puzzle. Much like those who run their aquarium water temperature close to the thermal maximums of corals walk a narrow tight rope, I can't help but think that low-nutrient aquariums may be headed down a similar path." Charles Delbeck, Coral Nov/Dec 2010, pg 127

Here's links to some of the research showing how important phosphate is and what can happen to a corals photobiology and physiology when corals can't get enough:

Nutrient enrichment can increase the susceptibility of reef corals to bleaching:
http://www.indiaenvironmentportal.org.in/files/file/Nutrient enrichment.pdf

Ultrastructural Biomarkers in Symbiotic Algae Reflect the Availability of Dissolved Inorganic Nutrients and Particulate Food to the Reef Coral Holobiont:
https://www.frontiersin.org/articles/10.3389/fmars.2015.00103/full

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
https://www.sciencedirect.com/science/article/pii/S0025326X17301601?via=ihub

Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental
approach
https://www.sciencedirect.com/science/article/pii/S0022098111004588

High phosphate uptake requirements of the scleractinian coral Stylophora pistillata
http://jeb.biologists.org/content/214/16/2749.full

 

[Timfish]

Glad you posted your experiences! Sadly the notion PO4 has to be kept low got ingrained in the reefer dogma in spite of the observations and comments of researchers who study reefs. J. E. N. Veron made this observation over 3 decades "Imported nutrients are usually transported to reefs from rivers; but if there are no rivers, as with reefs remote from land masses, nutrients can only come from surface ocean circulation. Often this supply is poor, and thus the vast ocean expanses have been refered to as "nutrient deserts". The Indo-Pacific has many huge atolls in these supposed deserts which testify to the resilience of reefs, but the corals themselves may lack the lush appearance of those of more fertile waters. Many reefs have another major supply of inorganic nutrients as, under certain conditions, surface currents moving against a reef face may cause deep ocean water to be drawn to the surface. This "upwelled" water is often rich in phosphorus and other essential chemicals." J. E. N. Veron "Corals of Austrailia and the Indo-Pacific" pg 30. Charles Delbeek wrote this observation and warning almost a decade ago "When I see the colors of some of these low nutrient tanks, I can't help but be reminded of bleached coral reefs. It should therefore not come as a surprise that feeding corals in such systems becomes a very important component in these systems. Though reefs are often catagorized as nutrient "deserts" the influx of nutrients in the form of particulates and plankton is quite high when the total volume of water passing over a reef is taken into consideration.

Our crystal-clear aquaria do not come close to the nutrient loads that swirl around natural reefs. And so when we create low-nutrient water conditions, we still have to deal with the rest of a much more complex puzzle. Much like those who run their aquarium water temperature close to the thermal maximums of corals walk a narrow tight rope, I can't help but think that low-nutrient aquariums may be headed down a similar path." Charles Delbeck, Coral Nov/Dec 2010, pg 127

Here's links to some of the research showing how important phosphate is and what can happen to a coral's photobiology and physiology when corals can't get enough:

Nutrient enrichment can increase the susceptibility of reef corals to bleaching:
http://www.indiaenvironmentportal.org.in/files/file/Nutrient enrichment.pdf

Ultrastructural Biomarkers in Symbiotic Algae Reflect the Availability of Dissolved Inorganic Nutrients and Particulate Food to the Reef Coral Holobiont:
https://www.frontiersin.org/articles/10.3389/fmars.2015.00103/full

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
https://www.sciencedirect.com/science/article/pii/S0025326X17301601?via=ihub

Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental
approach
https://www.sciencedirect.com/science/article/pii/S0022098111004588

High phosphate uptake requirements of the scleractinian coral Stylophora pistillata
http://jeb.biologists.org/content/214/16/2749.full

 

[Comic_Reef]

Great discussion/ info. Find myself in this predicament now. Zero PO4, Zero cyano, zero macro, zero GFO in system for months, few corals were looking “off” have been checking, checking, and checking some more. Got a new PO4 kit (Salifert) and consistently getting 0 PO4 as I was with prior kit, and somewhere btwn 50-100 on N03 color scale. I have increased feeding a little and let the cubes melt in a net sitting in the sump hoping that would help the PO4 but to no success after 2 weeks. I have ordered NeoPhos, which should be here today, to try dosing some PO4 as mentioned prior in the thread.

One product I see recommended a lot when people suspect metals, or have confined metals by ICP, is PolyFilter. PolyFilter will remove some metal however it removes all forms of phosphate at a much faster rate. Found this out the hard way after I applied the PolyFilter for elevated zinc and iron, the corals were not responding well and I was still blaming metals for the decline in health. After searching for more info I found that the PolyFilter is profoundly good at PO4 reduction versus metals absorption. Several high end colonies later I find that zero PO4 was likely the culprit the entire time.

Thanks for the Redfield Ratio info and the info from your personal experience with this matter.

Did you start dosing? What were your results. Your situation sounds almost entirely like what I was experiencing.

 

[ADAM]

Did you start dosing? What were your results. Your situation sounds almost entirely like what I was experiencing.

I never dosed the neophos. I did start thawing frozen cube food in the tank. I would feed one cube on day 1 and then day 2 I thawed a cube but didn’t add the food. Repeated this for 6 more days and then went back to feeding as normal with the exception of thawing the cube in the water column. Everything has seemed to level out since then.
On a side note, I do not use Carbon or GFO at all on this tank either.

 

[im_jeremy5]

If anyone wants to nerd out on the interactions of carbon, nitrogen, and phosphorous here is a decent link. After my researching due to my low phosphate high nitrate issues I ended up down this rabbit hole:

Phosphorus cycle (video) | Ecology | Khan Academy

Introduction to the phosphorus cycle. How phosphorus is recycled from phosphate to ATP and DNA.

www.khanacademy.org

 

[Michael Gray]

does polyfil really remove phosphate faster. I use amedia basket and use a mesh sock in the first compartment and polyfil on second.. finally i get like 10ppb po4 at night after lights out from multiple feedings and in morning when i wake up ill end up with about 3ppb. sometimes 0.. and when it tests zero i dose a smal 1ml of my potassium po4 and brings it up to about .04 to start day. my no3 is now about 6-8ppm

 

[Michael Gray]

since my goal is acros. im trying to maintain 5-10ppm no3 and detectable po4 but id love .04

 

[AngryMongol]

I just registered to say that I am going through the exact same problem. Sky high nitrates. Using the API test, the water turns blood red within seconds. Nothing is doing terrible but nothing is thriving either. When I first set up the tank, it sat fallow for a few months. It had sand and rock and everything. It just took me a while to stock it after it cycled. During that time, I was running phosguard. I added it because I run it in my other tanks and I find that it helps with heavy feeding phosphate rich foods. I don't rinse frozen food and I make it rain with formula two garlic pellets. My fish love those pellets.

Anyway, unknowingly the tank was already phosphate limited from the get go with phosguard stripping out what little it had. I never dosed phosphates before and I just use reef crystals for water changes one in a blue moon. Initially, corals showed some growth but nothing really took off. I did notice after heavy feedings my encrusting monti would grow noticeably overnight and would stop until I fed heavy again. Over time, nitrate kept going up and water changes were not helping at all. I was doing 50% water changes as fast as my rodi unit would produce and it would always go back up.

Luckily, i found this post a couple weeks back and everything just clicked. I immediately removed phosguard from my sump and started dosing neophos. My nitrate is still sky high and phosphate is being consumed like crazy, just like you. I added 2 ml of neophos to my ~85 gallon volume tank. I tested the water before I dosed and the color was just pale yellow meaning 0. I tested right after adding and it color came up to a nice green color. Then I checked 3 4 hours later and it was all GONE. Since then, I have been dosing 2ml in the morning and 2ml in the evening. The encrusting monti has been growing crazy since which makes me hopeful I can get nitrates down to a good range.

I have spent hours reading various forums and blogs and there were a lot of people having high nitrate issues. However, to them, 5 or 10 ppm was high and at 30 40 ppm they were talking like the antichrist has spawned in their tank or something. On the other hand, my tank have 160+ ppm nitrates and I am amazed at how resilient these creatures are. The corals and fish have been there for months and other than couple pulsing xenia and hydnophora frags, nothing has died off. Hopefully i can get behind this soon

 

[SiD]

Good afternoon,

First off, I am only leaving this here as a place for new and intermediate reefers to find some information. I by no means claim to be an expert but am only providing this "trial, error and success" steps that I took to solve a major problem that I do not see discussed very much, nor covered in many articles. Largely information I had to piece together and risk testing on my own. This is largely because it doesn't seem to be a very common problem. Seeing as I almost quit the hobby myself over it, I know that there is someone else out there struggling with the same problem and/or wanting to shut their system down.

The problem:
High Nitrates and Low Phosphates. By high nitrates I mean constantly rising, off the charts nitrates with phosphates at or "near-zero". Something like 100ppm NO3 and 0.02 phosphate.

The symptoms:
Nitrates will not come down. Phosphate will not go up. You have a good skimmer thats not pulling much, youve maybetried carbon dosing, a refugium or a denitrator, you're doing large water changes (50%+) multiple times a week but the nitrate just shoots back up within a day. You've cleaned everything you can, have no visible dead spots. Zero to very small amounts of Algae Growth. Water looks clean. Corals seem to be okay but don't thrive, some die fairly quick. SPS dies at an almost 100% rate.

The cause:
In short, it could be a lack of phosphate. For me it was GFO stripping all/most PO4. But for others it could be something else that disproportionately removes more PO4 that NO3.

Things to take into consideration:
Redfield Ratio. There is a lot of information here so I urge you to look into it if you are having this problem. The basics of it are as such: 106 Carbon to 16 Nitrogen (Nitrate) to 1 Phosphate. Now there is a lot of discussion surrounding Redfield Ratio and the importance of aiming for it, however it does illustrate that organisms in the home aquaria that dispose of Nitrate do require phosphate and carbon in order to do so. If you are at 100ppm NO3 and 0.02 PO4, you are at a NO3 to PO4 ratio of 5000:1. This will undoubtably hinder NO3 reduction.

The solution:
- Disable all phosphate removal media and go back to basics. Absolutely no GFO.

- Use the redfield ratio as a loose guideline and SLOWLY rebalancing the system through phosphate dosing. Depending on how out of whack your system is, you can do this from simply feeding more "high-phosphate" foods or dosing something like Brightwell's NeoPhos. I chose NeoPhos as I didn't want decomposing extra food to exacerbate the nitrate problem since I was over 100ppm Nitrate already.

- Test Phosphates daily. I recommend getting a Hanna ULR Phosphorous Checker to save you time. Pay attention to what youre bottoming out at. For me, my readings consistently came back 0.02. Most advice will tell you this is a great number to be at, however due to the steadfastness of this number, I believe that my results were actually zero. These tests can have a margin of error.

- Dose Safe Amounts of Phosphate Daily. if you are seeing a consistent zero or near zero measurement, dose a small amount of phosphate that, per instructions, should bring you up to say .04 total ppm. Test the following day and see where you are at. If you are back down to your zero/near zero levels, this is a "good sign". Something is consuming your phosphate. Something needed it. Do that for a week and if you keep coming back to zero daily, up the dose to bring you to .08 and test daily again. Your phosphate could be going one of a few places: Absorbed by rock, consumed by bacteria or consumed by algae. You may start seeing small, decreases in your nitrates at this point. If ever you test and the level hasn't come down to your original zero/near zero reading do not dose. You do not want to over do it because it can have negative side effects on your living organisms in high amounts.

- Pay attention to the algae/cyano. If ever a meaningful amount algae begins to pop up, stop dosing phosphate and see what happens to the algae. If it grows, there is still phosphate in the water, if it dies that means that there isnt. Essentially treat the algae like a visual representation of the denitrifying bacteria who are also vying for the same PO4 and NO3.

My end experience:
When I first dosed PO4, my tank was absorbing it at an absurd rate (.08 gone in 2 hours) and I had no algae. This gradually slowed down over time (.08 in 2 days) with small amounts of Cyano. My nitrate dropped from 100+ to a consistent 50 at about the 2 month mark with medium amounts of Cyano after each dose. At this point dosing once every 2-3 days. This tanked to 10ppm about a month later with a huge cyano outbreak after one of the doses. I siphoned this out as it signified the end of the need to dose as the PO4 was being mostly absorbed by algae. My phosphates still remain in the .04 range with Nitrate at 5.

Again, this I am not an expert nor claim to be. Just sharing my experience in hopes that it might help someone like me who was really struggling for a very long time with this issue. If it helps 1 person, I'm glad I took the time to post. Please call me out if something is wrong or you have any questions.

Happy reefing and happy new year

Dosed Monopotassium Phosphate and Nitrate went down to to 20 from 60 in a week.

 

[Comic_Reef]

I just registered to say that I am going through the exact same problem. Sky high nitrates. Using the API test, the water turns blood red within seconds. Nothing is doing terrible but nothing is thriving either. When I first set up the tank, it sat fallow for a few months. It had sand and rock and everything. It just took me a while to stock it after it cycled. During that time, I was running phosguard. I added it because I run it in my other tanks and I find that it helps with heavy feeding phosphate rich foods. I don't rinse frozen food and I make it rain with formula two garlic pellets. My fish love those pellets.

Anyway, unknowingly the tank was already phosphate limited from the get go with phosguard stripping out what little it had. I never dosed phosphates before and I just use reef crystals for water changes one in a blue moon. Initially, corals showed some growth but nothing really took off. I did notice after heavy feedings my encrusting monti would grow noticeably overnight and would stop until I fed heavy again. Over time, nitrate kept going up and water changes were not helping at all. I was doing 50% water changes as fast as my rodi unit would produce and it would always go back up.

Luckily, i found this post a couple weeks back and everything just clicked. I immediately removed phosguard from my sump and started dosing neophos. My nitrate is still sky high and phosphate is being consumed like crazy, just like you. I added 2 ml of neophos to my ~85 gallon volume tank. I tested the water before I dosed and the color was just pale yellow meaning 0. I tested right after adding and it color came up to a nice green color. Then I checked 3 4 hours later and it was all GONE. Since then, I have been dosing 2ml in the morning and 2ml in the evening. The encrusting monti has been growing crazy since which makes me hopeful I can get nitrates down to a good range.

I have spent hours reading various forums and blogs and there were a lot of people having high nitrate issues. However, to them, 5 or 10 ppm was high and at 30 40 ppm they were talking like the antichrist has spawned in their tank or something. On the other hand, my tank have 160+ ppm nitrates and I am amazed at how resilient these creatures are. The corals and fish have been there for months and other than couple pulsing xenia and hydnophora frags, nothing has died off. Hopefully i can get behind this soon

I know it's been a while. Wanted to see if you managed to get those nitrate down.

 

[Reef and Dive]

Your reports are pretty consistent with what we have discussed here:

https://www.reef2reef.com/threads/redfield-ratio-revisited-–-what-are-we-doing-wrong.742503/

 

[SiD]

I know it's been a while. Wanted to see if you managed to get those nitrate down.

BN was into STN , nothing was helping till I found @Randy Holmes-Farley recipe of Monopotassium Phosphate. BN coloured up in 2 days.
It is absolutely consistent with the notion of @Comic_Reef regarding necessity of Phosphate in reef tank.

Before dosing:

After 2 days of dosing Phosphate :

 

[Comic_Reef]

Your reports are pretty consistent with what we have discussed here:

https://www.reef2reef.com/threads/redfield-ratio-revisited-–-what-are-we-doing-wrong.742503/

My back and forth with Phosphate over the past few years has led me to believe phosphate is just as important to coral health as alkalinity and salinity. Stability of it isn't as necessary but it's presence, lack thereof and over abundance is something I don't think is emphasized enough when we discuss individual coral species and their needs and tolerances of phosphate.

 

[NowGlazeIT]

For me personally, it was my last attempt. I was in the "nothing to lose" stage since I had lost many of my coral slowly over time when this happened. GFO in my opinion can be just as damaging as a lot of other nutrient control methods. It's commonly warned not to overdose, and I personally found out why. It's something that, in my opinion has to be corrected quickly (putting some phosphates back in somehow) or, as in my case, it can cause a runaway nitrate problem.

I battled high nitrates until recently trying to add po4 to help lower them and in month I went through a bottle of neophos and my nitrate went from 80 to 20, my phosphates are still very low but I’ve stopped dosing to see if nitrates climb again. I used gfo and I think that may have caused my nitrates to climb also. Really wish I found this thread when I was troubleshooting high nitrates and low phosphates. I know this will help the next reefer along so thank you for this wonderful write up. Fwiw I used nopox and a oversized skimmer to combat my elevated nutrients

 

[SaltFishTV]

I’m glad I stumbled on this post! Did some phosphorus dosing last night and it dropped my 32 for two days in a row (was sitting still at 50) nitrate to 25 and .07 phosphate. I kept having the same issue where my phosphate would stick to .02 or 0 even after heavy feeding. Now I have some uglies like algae and cyano. It’s ok it’ll buff out!

 

[watchguy123]

Nitrates and phosphates too high or too low inhibit coral growth. Massive water changes are fraught with risk because although they may solve one issue , massive dilution may create new unique issues.

Constant testing and observation are both obligatory although observation is a lot more fun than testing. Trends are better to follow than absolute numbers because it’s easier to spot erroneous readings with observing trends ands if you decide to intervene, it should not be at a cataclysmic point.

dosing either nitrate or phosphate usually is not a long term plan unless you’re pretty comfortable with understanding your tank chemistry although it can be a short term solution to rebalance your tank. Ideally you want to find a balance that your tank can maintain with the least amount of effort

 

[NowGlazeIT]

Nitrates and phosphates too high or too low inhibit coral growth. Massive water changes are fraught with risk because although they may solve one issue , massive dilution may create new unique issues.

Constant testing and observation are both obligatory although observation is a lot more fun than testing. Trends are better to follow than absolute numbers because it’s easier to spot erroneous readings with observing trends ands if you decide to intervene, it should not be at a cataclysmic point.

dosing either nitrate or phosphate usually is not a long term plan unless you’re pretty comfortable with understanding your tank chemistry although it can be a short term solution to rebalance your tank. Ideally you want to find a balance that your tank can maintain with the least amount of effort

Nailed it

 

[Blue man92]

Thank you so much for sharing this with us. i am experiencing this exact problem at the moment with my tank and after reading this I have removed all Gfo(carbon) from my tank to hopefully re balance my tank fingers crossed.