High Nitrate - Low Phosphate

[Comic_Reef]

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.

Glad it can be of use.

Just ensure you stay patient, go slow and most importantly.... Read Your Corals.

They ultimately will tell you if their environment is good or not. People with happy tanks and bad numbers should stay the course unless or until their corals tell them to change it.

 

[NewReeferKev]

My tank is experiencing similar with a slightly less extreme case. My nitrates consistently sit around 30-40 for the last month. Corals are staying retracted and obviously stressed. Water changes are not seeming to have any effect at all. Phosphate stays bottomed out even with an additive. I was too afraid to add more in fear of it swinging horribly out of control. Seems like that is exactly what I need to do. Very new, and very afraid to make big mistakes that hurt the animals, or hurt the habitat. Thank you for the detailed write up. I have hope that it can be corrected again thanks to you, rather than sitting helpless watching everything struggle.

 

[Cbones1979]

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

This is old but I’m actually the opposite. Nitrates at dropping from 5.4 to 2.5 and phosphates rising to .13 from .07

 

[Tritie]

This is very close to my three month long nightmare with my 65 gallon sysyem from hell. I only have a few fish, no coral, and small led just to let the fish know the time. Nitrates increase by 20 ppms a week. 50% water changes are done mostly weekly. Last interval was 10 days and I was at 57ppm. Now down to 30ppm after a water change. Phos is 0.00-0.02 though to be honest I am using Hanna LR, but Salifert confirms this. I intended to purchase the ULR Hanna phos, but grabbed the wrong one. Chaeto is a tight dark green wiry ball that doesnt grow, protein skimmer is not doing much. Filter socks or floss changed every day to every two days. I tried dosing AquaVitro P as it was the only one available at 2 lfs near me. Sometimes I wonder if Hanna reagents react with the phos source in that one. Anyone have any ideas? I did just order NeoPhos. I've tried carbon dosing with NoPox and get blooms on the glass. I stopped both NoPox and AquaVitro phos as they did not seem to be helping. Will try this method again to see if it can help me, with the Neophos.

 

[Comic_Reef]

This is very close to my three month long nightmare with my 65 gallon sysyem from hell. I only have a few fish, no coral, and small led just to let the fish know the time. Nitrates increase by 20 ppms a week. 50% water changes are done mostly weekly. Last interval was 10 days and I was at 57ppm. Now down to 30ppm after a water change. Phos is 0.00-0.02 though to be honest I am using Hanna LR, but Salifert confirms this. I intended to purchase the ULR Hanna phos, but grabbed the wrong one. Chaeto is a tight dark green wiry ball that doesnt grow, protein skimmer is not doing much. Filter socks or floss changed every day to every two days. I tried dosing AquaVitro P as it was the only one available at 2 lfs near me. Sometimes I wonder if Hanna reagents react with the phos source in that one. Anyone have any ideas? I did just order NeoPhos. I've tried carbon dosing with NoPox and get blooms on the glass. I stopped both NoPox and AquaVitro phos as they did not seem to be helping. Will try this method again to see if it can help me, with the Neophos.

So I would try the phosphate if you're not seeing any algae. Especially in a newer tank, I found that the rock itself may be swallowing up the phosphate starving the rest of the tank is the phosphate it needs. My own personal experience has taught me that anything sub 0.03 could in reality be margin of error and may actually be zero. Especially if I have no algae and the glass stays clean for more than a few days. Im by no means an expert but I would maybe try to maintain 0.03-0.05 testing multiple times a week to see if nitrate comes down. For a while, mine just dropped back down to 0 to 0.02 every time I dose P. The suddenly the nitrate tanked quickly

 

[Tritie]

I have the Fluval evo stock light on the tank. As i said, its just there so the fish have some sort of light, but all I'm getting a brownish rusty growth on rocks and sand which I assume are diatoms.

 

[Tritie]

I dosed phos up to 0.19ppm last night according to my Hanna LR. As I don't have any corals in the tank, I thought I would see what it would do, and given my nitrates are so high, big water changes are a must, so I can easily pull out the phos if I had to. Tonight, 24 hours later, Hanna LR detected 0.00. Dosed it again.

 

[Randy Holmes-Farley]

big water changes are a must, so I can easily pull out the phos if I had to.

What you are doing seems fine to me, but I would be cautious about that assumption. Since phosphate can bind to rock and sand, and the amount that binds is related to the concentration in the water, if you have substantially elevated phosphate, even a 100% water change amy not reduce it all that much as more will come off the rock and sand to replace it.

The same is not true of nitrate, and it is easily removed by water changes of sufficient size.

 

[Tritie]

What you are doing seems fine to me, but I would be cautious about that assumption. Since phosphate can bind to rock and sand, and the amount that binds is related to the concentration in the water, if you have substantially elevated phosphate, even a 100% water change amy not reduce it all that much as more will come off the rock and sand to replace it.

The same is not true of nitrate, and it is easily removed by water changes of sufficient size.

Perfect. Thank you so much for informing me of this. I got up earlier to test the phos before work (Hanna LR) to see how much would be left from last nights dose, and again it read 0.00. Even though I am using the LR, it seems that much is being used up in a 12 hour period, let alone a 24 hr period. To help with my nitrate situation, I added new chaeto 2 nights ago. I'm wondering if I should take it out until I get a handle on the low phos situation? Or is it unlikely to strip out 0.2ppm in a 2 hr period. It it a large ball of chaeto (1/2 the size of a soccer ball) and right now I'm running a Neptunian Cube fuge light.

 

[Randy Holmes-Farley]

Perfect. Thank you so much for informing me of this. I got up earlier to test the phos before work (Hanna LR) to see how much would be left from last nights dose, and again it read 0.00. Even though I am using the LR, it seems that much is being used up in a 12 hour period, let alone a 24 hr period. To help with my nitrate situation, I added new chaeto 2 nights ago. I'm wondering if I should take it out until I get a handle on the low phos situation? Or is it unlikely to strip out 0.2ppm in a 2 hr period. It it a large ball of chaeto (1/2 the size of a soccer ball) and right now I'm running a Neptunian Cube fuge light.

I do not think the chaeto is the issue. It's likely the rock and sand. I'd just keep dosing phosphate.

 

[Tritie]

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

Were you carbon dosing or doing any water changes during these three months that may have helped bring nitrates down in those 2 months?

 

[Tritie]

Thank you for this thread, and thanks to everyone for their help! I've dosed a huge amount to phos over the last couple months. Whether by having some ratio of phos to nitrate, some phos for the new chaeto to grow and pull out some nitrates or both, by March, I was only seeing a 12-14ppm increase in nitrate weekly. Pretty good considering it was increasing by 24-26ppm per week. For the last couple weeks, I've been using Tropic Marin NP Plus, and my nitrates are only climbing by about 2-5ppm per week despite having more fish now then back in Feb. I'll be switching over to the Tropic Maring Bacto Balance on Monday. Thanks again.

 

[Comic_Reef]

Thank you for this thread, and thanks to everyone for their help! I've dosed a huge amount to phos over the last couple months. Whether by having some ratio of phos to nitrate, some phos for the new chaeto to grow and pull out some nitrates or both, by March, I was only seeing a 12-14ppm increase in nitrate weekly. Pretty good considering it was increasing by 24-26ppm per week. For the last couple weeks, I've been using Tropic Marin NP Plus, and my nitrates are only climbing by about 2-5ppm per week despite having more fish now then back in Feb. I'll be switching over to the Tropic Maring Bacto Balance on Monday. Thanks again.

Fantastic news! That was my exact purpose for writing this out. If I could help a single person, I wanted to be able to do so. Especially as a situation that doesn't seem to effect very many people. Most imbalance discussion revolved around high phosphate low, low nitrate environments. Happy to help! HAPPY REEFING!

 

[Rylan5d]

Dealing with the exact same stuff. A friend suggested dosing Phosphate to help lower them, and then stumbled on this.

Nitrate above 75ppm and flashing lol (Hanna HR Nitrate)
Phosphate 0.03-0.01 (Hanna Phosphate ULR)

Have pretty much given up hope on my tank, lost some frags, and such. Hoping this may give me some help, and some relief lol

 

[Tritie]

Everytime I post a positive message about my tank with respect to this topic, karma knocks me down a few notches. However, I seem to be "staying" somewhere, rather than slowly getting there. Dosing phos, vodka, and microbacter7. Also have a refugium as well as a protein skimmer, both of which are not perfectly tuned. My guess is that the phos and carbon dosing are the biggest contributors. I'm dosing about 0.07ppm of phos 3x per day now. Significantly less than what I had been dosing. I did not start adding coral (except gsp and xenia) until July this year. It let me play with spiking the phos to see how it was coming down. I only had a Kessil A80 over the xenia and gsp so didn't have much of an algae bloom at first. I did in July when i turned on my main lights, but snails and peroxide treatments have cleared it up. It is starting to feel like less of a battle now. I can get away with a 10% water change every 2 weeks now. In Dec/Jan of last year I was doing 3 x 50% water changes a week. I only had a single chromis in there at the time and so the 200ppm nitrates were mind boggling.

 

[officialreefbros]

Would you recommend dosing more phos if it's stable around <0.05? I was actively carbon dosing and dosing phos to get my nitrates down to <10. I installed a new light and lost room for the skimmer so stopped carbon dosing. Now my nitrates keep climbing fast and my phos is mostly stable or slightly going down.

 

[Randy Holmes-Farley]

Would you recommend dosing more phos if it's stable around <0.05? I was actively carbon dosing and dosing phos to get my nitrates down to <10. I installed a new light and lost room for the skimmer so stopped carbon dosing. Now my nitrates keep climbing fast and my phos is mostly stable or slightly going down.

If it is stable at 0.04 ppm, I wouldn't bother dosing phosphate, but it's fine to do so. If it is stable at anything less than 0.03 ppm, I'd dose it up.

 

[ReefJunkie82]

So this seems to be the case for me also, tank has been running since May this year, only recently I have noticed the decline in coral health and even lost a few. So I have been dosing po4 as suggested but am curious of how soon I will expect the po3 to drop in to range. Head wreck is an understatement. All other parameters are good other the nutrients being out of wack. Any advice would be greatly appreciated

 

[dor_L]

GREAT POST,I LURN NEW INFO ABOUT THE no3 AND po4

I HAVE SAME PROBLEM WITH HIGH NO3 AND LOW po4

 

[colebartholow]

This might be a lifesaver.

I set this tank up a little over two years ago. I filled it with mostly LPS and some SPS coral about a year ago. The coral all slowly died except for my softies and a few LPS that are still barely hanging on.

I never understood because my calcium alkalinity were always on point and I just didn’t understand. My nitrates were always 15 to 20 but might phosphorus/phosphates were always zero. I’ve kind of given up over the last six months and kinda just let everything run its course so I’m hoping that I can try this and see what happens.