Balancing the chemical compounds in your reef: Do you pay attention to the nitrate-phosphate balance?

[2Wheelsonly]

I just make sure one is not bottoming out. I tried testing to see what triggered cyano but after 14 years in the hobby have yet to figure out what truly causes it to come and go. I have had it vanish and outbreak with all kinds of different levels.

 

[Tonycass12]

I think the ratio thing is garbage. I test for both to make sure I'm not having any big swings but my system runs high PO⁴ for the last year or so. For the last couple months phosphates have been at .5 but were nearly as high as .8 and my nitrates sit right around 30. So long as the corals continue to look good and grow like weeds I'm not going to stress over the numbers.

 

[Azael]

I only test the phosphates

 

[Jeroen1975]

Balancing the chemical compounds in your reef: Do you pay attention to the nitrate-phosphate balance?

It seems like there used to be a lot more of a focus on the balance between nitrate and phosphate. While the Redfield ratio (comparing carbon, nitrogen, and phosphorus) is occasionally mentioned, it doesn’t appear to be a common point of discussion. When the relationship between nitrate and phosphate is brought up, I have heard ratios of 16:1, 15:1, 10:1, and more. Regardless of what ratio that you use, do you pay attention to the nitrate-phosphate balance in your marine aquarium? Please let us know your experience and any tips that you have to share with the R2R community!

Photo by @youramigojake


This QOTD is sponsored by: www.deltecdirectusa.com

“With dozens of protein skimmers, calcium reactors, media reactors and kalkwasser stirrers in operation, Deltec USA can speak from experience and help you with all your Deltec needs. Live customer support and a large inventory of products rounds out our mission to provide the best possible Deltec experience.”

What if I'm bottoming out?

I came from zero, fought an algae outbreak, no3 rose to 25mg/l, Phosphorus 0. Then dosed PO4, feed a bit more, week later no3 1mg/l, Phos again 0. Rocks stay clean but glass build up a film in a couple of hours.

 

[Randy Holmes-Farley]

What if I'm bottoming out?

I came from zero, fought an algae outbreak, no3 rose to 25mg/l, Phosphorus 0. Then dosed PO4, feed a bit more, week later no3 1mg/l, Phos again 0. Rocks stay clean but glass build up a film in a couple of hours.

If both N and P bottom out, add them back until you get at what you consider a good target range of values. They are cheap and easy to dose in food grade quality.

I recommend 2-10 ppm nitrate and 0.03 to 0.1 ppm phosphate.

 

[Jeroen1975]

If both N and P bottom out, add them back until you get at what you consider a good target range of values. They are cheap and easy to dose in food grade quality.

I recommend 2-10 ppm nitrate and 0.03 to 0.1 ppm phosphate.

Thnx Randy. I was dosing phos allready cause it bottoms out, even with a low range phosphorus checker. But it seems to pull down no3 to. So Im kinda hesitant.... what to do?

 

[Randy Holmes-Farley]

Thnx Randy. I was dosing phos allready cause it bottoms out, even with a low range phosphorus checker. But it seems to pull down no3 to. So Im kinda hesitant.... what to do?

Feed more or dose both. Both methods work.

 

[Hans-Werner]

So the coral bleaching that occurs when phosphate becomes limited is the coral consuming it's zooxanthellae?

Or rather, the coral is always consuming it's zooxanthellae at a constant rate, and with nutrient limited conditions the dinoflagellate reproduction can't keep up?

The experiments had N and P limiting or replete. The corals bleached when N and P were limiting.

Both is true. The corals are consuming their zooxanthellae. Under nutrient limited conditions the growth of the zooxanthellae number slowed down. The corals continued to consume zooxanthellae, initially at a constant rate. Bleaching was caused by reduced zooxanthellae growth shown in the lower mitotic index under nutrient-limited conditions, so consumption reduced number or zooxanthellae resulting in a bleached appearence.

"To model the decline of symbiont numbers in our model corals
(M. foliosa, M. capricornis, S. pistillata and A. polystoma) grown under
nutrient-limited conditions, we used the same formula with the division
rate of 3.5 ± 0.7% and a lower proliferation rate adjusted for reduced
mitotic indices of the symbionts exposed to nutrient-limited conditions
(0.8 ± 0.16%) (Supplementary Fig. 1, M12)."

Hans, can you fix the first link?
It's labeled "this study from Florida". I can't get it to work.

This is the direct link to the PDF again. Sometimes such links don't work because sharing seems to be blocked somehow. Here is a link to a store of the publication. Maybe it works if you copy the headline of the publication and insert it into a search at scholar.google.

I unterstand it right deplete experiment was 0.7 nitrate and 0.13 Phosphate and enriched 12 Nitrate and 3 Phosphate? and the second group performed better? 3 Phosphate seems very high

These are µM concentrations. 1 µM = 62 ppm NO3- or 95 ppm (PO4)3-. So 12 µM Nitrate are 0.744 ppm and 3 µM Phosphate are 0.285 ppm.

 

[Belgian Anthias]

Balancing the chemical compounds in your reef: Do you pay attention to the nitrate-phosphate balance?

It seems like there used to be a lot more of a focus on the balance between nitrate and phosphate. While the Redfield ratio (comparing carbon, nitrogen, and phosphorus) is occasionally mentioned, it doesn’t appear to be a common point of discussion. When the relationship between nitrate and phosphate is brought up, I have heard ratios of 16:1, 15:1, 10:1, and more. Regardless of what ratio that you use, do you pay attention to the nitrate-phosphate balance in your marine aquarium? Please let us know your experience and any tips that you have to share with the R2R community!

Photo by @youramigojake


This QOTD is sponsored by: www.deltecdirectusa.com

“With dozens of protein skimmers, calcium reactors, media reactors and kalkwasser stirrers in operation, Deltec USA can speak from experience and help you with all your Deltec needs. Live customer support and a large inventory of products rounds out our mission to provide the best possible Deltec experience.”

A balance between nitrate and Phosphate? What is the relation between phosphate and nitrate production or availability? Nitrate is an end-product of natural remineralization and is produced in function of the C/N ratio of the feed and of the food added, supporting heterotrophic or and autotrophic bacterial growth . If the C/N ratio is high enough, no nitrate is produced. Are we talking about a balance between phoshate absorbtion and releas in function of nitrate availability? Nitrate is constantly removed by natural de-nitrification, by anaerobic remineralization, by anaerobic heterotrophic growth, Phosphate measured in the watercolumn is not removed. What relation or balance are you talking about?

 

[Hans-Werner]

These are µM concentrations. 1 µM = 62 ppm NO3- or 95 ppm (PO4)3-. So 12 µM Nitrate are 0.744 ppm and 3 µM Phosphate are 0.285 ppm.

Sorry, 1 µM = 62 ppb NO3- or 95 ppb (PO4)3-

 

[Timfish]

Looks like a good opportunity to use one of my soap boxes. What bugs me about people advocating the use of Redfield ratios is they're not considering all the forms of Carbon, Nitrogen and Phosphorus. Invariably only the inorganic forms nitrate and phosphate is being considered. Particulate organic forms as well as dissolved organic forms aren't mentioned and don't seem to be ever considered. Chasing "ideal" ratios while ignoring different forms available for organisms understandably leads to confusion, frustration and failure.

 

[Dburr1014]

Looks like a good opportunity to use one of my soap boxes. What bugs me about people advocating the use of Redfield ratios is they're not considering all the forms of Carbon, Nitrogen and Phosphorus. Invariably only the inorganic forms nitrate and phosphate is being considered. Particulate organic forms as well as dissolved organic forms aren't mentioned and don't seem to be ever considered. Chasing "ideal" ratios while ignoring different forms available for organisms understandably leads to confusion, frustration and failure.

They are the most important but get shuffled under the rug because we can't test for them.