What is your N/P ratio?

[WrasseyReefer]

Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates

Enrichment of reef environments with dissolved inorganic nutrients is considered a major threat to the survival of corals living in symbiosis with dinoflagellates (Symbiodinium sp.). We argue, however, that the direct negative effects on the symbiosis ...

www.ncbi.nlm.nih.gov

This paper is really interesting and has been discussed on R2R before, but I wanted to find out where people keep their N/P ratio. While we know that 16:1 is the ideal N/P ratio, it’s definitely difficult to attain and maintain, so we do our best to maintain our nitrates and phosphates at values that we think work best. I’m curious where other reefers tend to keep their nitrates and phosphates and where that lands their N/P ratio.

The paper basically shows that high nitrates/high phosphorous is ideal, but low nitrate/high phosphate “corals suggest that the N-limitation sustains a slower but chemically balanced growth while maintaining a functional photosynthesis.”

High nitrate/low phosphorous and low nitrate/low phosphorous “conditions were more susceptible to bleaching when exposed to heat stress and/or elevated light levels (Wiedenmann et al., 2013). The detrimental effects were linked to the relative undersupply with phosphorus that can result from the higher demand of the proliferating algal populations rather than to the high nitrogen levels.”

 

[Timfish]

One of the points that caught my eye in that paper is the N : P ratio on reefs

"In coral reef waters, N : P ratios were found in an approximate range from 4.3:1 to 7.2:1"

 

[rtparty]

16:1 is NOT the ideal ratio. There is no nitrate to phosphate ratio.

The often over used and misunderstood Redfield ratio is the ratio of nitrate and phosphate in certain organisms. Not in the water surrounding those organisms. N and P in the ocean is actually very low.

Looking up posts from Hans Werner on the topic is very educational. He debunks the whole ratio and how pointless it is for our use

 

[Garf]

high nitrates/high phosphorous is ideal

I bet their “high” is not my “high” lol

 

[Garf]

My post regarding “high” was deleted as being not very family friendly. I was merely pointing out that the “high” phos and nitrate in these tests were probably not as high as I would consider high.

Guess in too innocent, or ignorant, hey ho

 

[WrasseyReefer]

16:1 is NOT the ideal ratio. There is no nitrate to phosphate ratio.

The often over used and misunderstood Redfield ratio is the ratio of nitrate and phosphate in certain organisms. Not in the water surrounding those organisms. N and P in the ocean is actually very low.

Looking up posts from Hans Werner on the topic is very educational. He debunks the whole ratio and how pointless it is for our use

Interesting. Would you mind sharing the Hans Werner posts you’re referring to? I’d like to learn more.

Here’s a paper that talks about the redfield ratio and how it indeed is the composition of these nutrients in phytoplankton but how the ratio is very similar in oceans.

https://www.science.org/doi/10.1126/sciadv.aaw9371

“In a seminal paper in 1934, Redfield proposed that the global spatial and temporal average C:N: P of POM (defined as the organic matter retained on 0.7-μm filters and composed mostly of phytoplankton cells) is constant and remarkably similar to the ratio of dissolved inorganic nutrients in the deep ocean, most likely as a result of the decomposition of POM into its constituents (5, 6).“

And I’m curious what your take is on this paper, since they did conclude that ratio does have an impact on coral health, growth, and bleaching. However, you’re saying you don’t think that ratios matter.

And yeah, 16:1 probably isn’t ideal anymore. I think it’s changed to 22:1 now. But yeah, I don’t know if there is an ideal since many people run their reefs at far from those ratios with much success. I’m interested in learning more about this topic.

Curious, where do you keep your nitrates and phosphates and where is your ratio at?

 

[WrasseyReefer]

My post regarding “high” was deleted as being not very family friendly. I was merely pointing out that the “high” phos and nitrate in these tests were probably not as high as I would consider high.

Guess in too innocent, or ignorant, hey ho

Yeah, I also thought that it was interesting that what the paper considers to be high nitrates and high phosphates are probably considered low in the hobby. And I wonder if they had used hobby high values for these instead but at the same ratios, if the results would’ve been the same.

Curious, where do you keep your nitrates and phosphates and what is your ratio?

 

[WrasseyReefer]

One of the points that caught my eye in that paper is the N : P ratio on reefs

"In coral reef waters, N : P ratios were found in an approximate range from 4.3:1 to 7.2:1"

Yeah, super low ratios compared to what hobbyists likely keep in their tanks. It’s interesting.

Where do you keep your nitrates and phosphates, and where does that land your N/P?

 

[apb03]

Tested yesterday at 25.5 Nitrate and 0.26 phosphate. I seem to usually end up at around 100:1.

 

[WrasseyReefer]

Tested yesterday at 25.5 Nitrate and 0.26 phosphate. I seem to usually end up at around 100:1.

How’s your growth, polyp extension, etc?

 

[apb03]

How’s your growth, polyp extension, etc?

Pretty decent I would say. My millies are doing great, my new Oregon tort finally had the polyps come out, pink lemonade and pinky the bear are flopping around, etc. Its hard to say if it's bad or good, but my corals look pretty happy to me.

Most surprising is my dynamite chalice is growing like crazy. 2 new eyes last week.

My mindset is I'd rather be high nutrient and not worry about dinos and let my tangs and cuc take care of any algae if it were to appear. Coral colour is good too.

 

[WrasseyReefer]

Pretty decent I would say. My millies are doing great, my new Oregon tort finally had the polyps come out, pink lemonade and pinky the bear are flopping around, etc. Its hard to say if it's bad or good, but my corals look pretty happy to me.

Most surprising is my dynamite chalice is growing like crazy. 2 new eyes last week.

My mindset is I'd rather be high nutrient and not worry about dinos and let my tangs and cuc take care of any algae if it were to appear. Coral colour is good too.

Yeah, I think what this paper fails to address is how these ratios can still be achieved at much higher nitrate and phosphate values. So you may be in the 100:1 ratio category (Low nitrates/low phosphates (N/P ~ 117:1), but you’re nitrates and phosphates are not actually low at all, and specifically, your phosphate is not undersupplied. Thanks for sharing your nutrient levels. It’s interesting to see what others are doing and how it works for them. Seems like what you’re doing is working well.

 

[apb03]

I hope so! I'm trying to just let the tank do it's thing and let the numbers be what they are. I am carbon dosing as well using the Tropic Marin suite. Adding 1ml a day of elimni np, so that also may be playing a role.

Not so much for the nutrient reduction but more for the beneficial bacteria from carbon dosing.

 

[WrasseyReefer]

I hope so! I'm trying to just let the tank do it's thing and let the numbers be what they are. I am carbon dosing as well using the Tropic Marin suite. Addi G 1ml a day of elimni np, so that also may be playing a role.

Yeah, I carbon dose as well, which definitely makes it a bit more tricky to manage N and P. But it’s all good. Have you had any algae issues?

 

[apb03]

Yeah, I carbon dose as well, which definitely makes it a bit more tricky to manage N and P. But it’s all good. Have you had any algae issues?

None whatsoever. I think that's mostly because of my Whitetail bristletooth tang. I had a fish in an acclimation box for a week with rock in there and it got covered in algae, moved it back out and it was clean the next day. That tang is a savage.

 

[WrasseyReefer]

None whatsoever. I think that's mostly because of my Whitetail bristletooth tang. I had a fish in an acclimation box for a week with rock in there and it got covered in algae, moved it back out and it was clean the next day. That tang is a savage.

Have you ever run your nitrates and phosphates lower? Did you see a difference?

 

[apb03]

Have you ever run your nitrates and phosphates lower? Did you see a difference?

It was much lower a couple of months ago at around 10nitrate and 0.08 to 0.1 phosphate, but didn't see much difference.

 

[Garf]

Yeah, super low ratios compared to what hobbyists likely keep in their tanks. It’s interesting.

Where do you keep your nitrates and phosphates, and where does that land your N/P?

Currently 0.3ppm PO4, 40 ppm NO3, but phos has been all the way up to 1.4ppm PO4. Similar story in my previous tank but that was nearly all soft corals.

 

[Randy Holmes-Farley]

. While we know that 16:1 is the ideal N/P ratio, it’s

I do not think it is desirable or even sensible for reefers to think of nutrient target levels as ratios. It just serves to lead to false conclusions.

It is never wrong, and usually far more informative to discuss the absolute levels of each.

For example, does it make any sense if N is very low, say, 0.001 ppm nitrate, for phosphate to also be very low, say 0.0001 ppm?

 

[rtparty]

Interesting. Would you mind sharing the Hans Werner posts you’re referring to? I’d like to learn more.

Here’s a paper that talks about the redfield ratio and how it indeed is the composition of these nutrients in phytoplankton but how the ratio is very similar in oceans.

https://www.science.org/doi/10.1126/sciadv.aaw9371

“In a seminal paper in 1934, Redfield proposed that the global spatial and temporal average C:N: P of POM (defined as the organic matter retained on 0.7-μm filters and composed mostly of phytoplankton cells) is constant and remarkably similar to the ratio of dissolved inorganic nutrients in the deep ocean, most likely as a result of the decomposition of POM into its constituents (5, 6).“

And I’m curious what your take is on this paper, since they did conclude that ratio does have an impact on coral health, growth, and bleaching. However, you’re saying you don’t think that ratios matter.

And yeah, 16:1 probably isn’t ideal anymore. I think it’s changed to 22:1 now. But yeah, I don’t know if there is an ideal since many people run their reefs at far from those ratios with much success. I’m interested in learning more about this topic.

Curious, where do you keep your nitrates and phosphates and where is your ratio at?

NP Plus - Phosphate / Nitrate ratio

According to previous threads on NP Plus, I am suppose to test phosphate only because nitrate is expected to remain 0 while using NP Plus. I did not know that at first so I kept dumping NP Plus and testing my nitrate. I finally got a Hanna Phosphate test kit and it is reading 0.39 for...

www.reef2reef.com

That’s a good start.

I don’t test N or P in my tanks. Not regularly at least. They get tested if I send off an ICP test a few times a year but that’s it.

Again, there is no such thing as a nitrate to phosphate ratio in nature. Shooting for one is a fools errand IMO