Nitrate- cannot get it to fall

[areefer01]

Not in my experience.

It is the all for reef ;)

Hope your day is well.

 

[JonasRoman]

Not in my experience.

Interesting. I think that at least tell us that coral may adapt to unnatural nitrate concentrations. Maybe not all though. In the study there was differences between species how much the oxidative stress due to elevated nitrate levels affected the coral. And as I said, ammonium can have a protective effect. Also, according to the study, the bad effect of high nitrate was exaggerated if po4 was low at same time.

 

[mcarroll]

Exact. But something it tells us, that corals may adapt to unnatural no3 levels I guess. But that still not the same as its good.

Most of what's wrong with elevated N in the wild is not that there is X level of NO3 in the water.

The "problem" is that there's nobody hanging around in the wild with a bottle of Flourish Phosphorous to balance things out.

That's why I keep this article pinned to the top on my blog:
Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
https://reefsuccess.com/2018/08/27/...-ultrastructure-of-symbiotic-dinoflagellates/

Even if you don't read it, the picture from Figure 1 of the article almost tells the whole story, from micro to macro:
L= Low H=High N=Nitrate P=Phosphate

 

[EnterName]

Most of what's wrong with elevated N in the wild is not that there is X level of NO3 in the water.

The "problem" is that there's nobody hanging around in the wild with a bottle of Flourish Phosphorous to balance things out.

That's why I keep this article pinned to the top on my blog:
Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
https://reefsuccess.com/2018/08/27/...-ultrastructure-of-symbiotic-dinoflagellates/

Even if you don't read it, the picture from Figure 1 of the article almost tells the whole story, from micro to macro:
L= Low H=High N=Nitrate P=Phosphate

Just a small addition, since I know this could easily be misunderstood otherwise:

Once PO₄ is above 0.03ppm, the N:P ratio becomes much less critical. So this study doesn't really apply to most reef tanks. However, if you want to keep your tank below 0.03ppm PO₄, you might want to keep N low as well.

"In our experiments, a phosphate concentration of ~0.3 μM at a N:P ratio of 22:1 yielded an overall healthy phenotype. Accordingly, it is likely that the absolute N:P ratio becomes also less critical for the proper functioning of the symbionts when phosphate concentrations exceed a vital supply threshold (>0.3 μM), even when the symbionts are rapidly proliferating." (Rosset et al., 2017, §4.3)

0.3μM PO₄ ≈ 0.0285ppm PO₄ ≈ 0.03ppm PO₄​

 

[mcarroll]

Just a small addition, since I know this could easily be misunderstood otherwise:

Once PO₄ is above 0.03ppm, the N:P ratio becomes much less critical. So this study doesn't really apply to most reef tanks. However, if you want to keep your tank below 0.03ppm PO₄, you might want to keep N low as well.

"In our experiments, a phosphate concentration of ~0.3 μM at a N:P ratio of 22:1 yielded an overall healthy phenotype. Accordingly, it is likely that the absolute N:P ratio becomes also less critical for the proper functioning of the symbionts when phosphate concentrations exceed a vital supply threshold (>0.3 μM), even when the symbionts are rapidly proliferating." (Rosset et al., 2017, §4.3)

0.3μM PO₄ ≈ 0.0285ppm PO₄ ≈ 0.03ppm PO₄​

You should run this experiment for yourself so you can see it apply. Doesn't take much looking here for threads where you can see evidence though...but that's not 1st hand which I think would help.

 

[EnterName]

You should run this experiment for yourself so you can see it apply. Doesn't take much looking here for threads where you can see evidence though...but that's not 1st hand which I think would help.

My tank is mostly running at 0.03 - 0.05ppm PO₄ and I'm targeting 2 - 5ppm NO₃, so I'm right in the range that would be considered very dangerous if the ratio still mattered that much above 0.03ppm PO₄. The tank has been running at these levels for multiple years (before that, my nitrate levels were even lower), both with and without additional coral feeding. I don't have a control tank to tell you whether growth has been "perfect", but my corals look healthy and colorful.

Does any of this matter? No, because it's anecdotal, and so are the threads here on R2R. To be honest, I don't consider "look around" a good source, especially since I'm quite active here so I'm constantly looking around.

We recently had a member whose N:P ratio and low phosphate levels put them right in the "dangerous" area, and I mentioned the same study there, so it does have its use. But for most tanks it might not matter that much, since many people keep pretty insane N:P ratios in healthy tanks
That's probably also why Randy thinks Liebig might be more interesting to reefers than Redfield (besides Redfield applying to plankton mass, etc.).

The study specifically mentions that the ratio most likely isn't that important anymore above roughly 0.03ppm PO₄. That makes sense, because at some point nitrogen uptake or transport within the cell will be limited by other factors, so having a lot more nitrogen available compared to PO₄ doesn't matter too much in that case.

 

[JonasRoman]

Most of what's wrong with elevated N in the wild is not that there is X level of NO3 in the water.

The "problem" is that there's nobody hanging around in the wild with a bottle of Flourish Phosphorous to balance things out.

That's why I keep this article pinned to the top on my blog:
Phosphate deficiency promotes coral bleaching and is reflected by the ultrastructure of symbiotic dinoflagellates
https://reefsuccess.com/2018/08/27/...-ultrastructure-of-symbiotic-dinoflagellates/

Even if you don't read it, the picture from Figure 1 of the article almost tells the whole story, from micro to macro:
L= Low H=High N=Nitrate P=Phosphate

Will read this article carefully later this week. Will be back if I have any questions

 

[mcarroll]

My tank is mostly running at 0.03 - 0.05ppm PO₄ and I'm targeting 2 - 5ppm NO₃, so I'm right in the range that would be considered very dangerous if the ratio still mattered that much above 0.03ppm PO₄.

Ratio? Not sure I follow.

To do the experiment, try limiting P in a manner similar to the "ULNS" way (thankfully less popular than it's ever been I think)...gradually take P lower and lower and see if/when corals eventually react as predicted by the science and demonstrated in the photo. Folks commonly use one of the two low-range phosphate meters from Hanna to assure levels this low.

Depending on your tank and its endogenous ability to feed your corals, and their ability to feed themselves, the experiment may or may not be any good. The better your reef tank is, the less good your experiment will be since your corals are less (or not) dependent on you directly for nutrition.

(Not that you need me to say it, but this is just talk, don't do this on a healthy reef tank. Do a separent experiment with frags in their own system if you decide to do this at all. )

That's probably also why Randy thinks Liebig might be more interesting to reefers than Redfield

Yes....Liebig suggests that limiting P will do what the research paper shows to happen. I have held that opinion based on observations within the hobby for a long time as you can see in the history of my comments here and elsewhere. IMO Liebig brings more people around to my way of seeing this aspect of the hobby. Redfield is of interest academically. You slap your forehead with the realization it brings (there can be multiple realizations!) and then you move on to Liebig's domain....the practical.

 

[Lasse]

Why are you discussing corals and NO3 in this thread? - What I understand - the OP has a FOWLR (Fish Only With Living Rocks) and it was not reef save hermits and fish that die (and one get blind)

I do not think that it is NO3 that cause the problems in THIS case. I have seen with large FO tanks with NO3 concentrations around 200 and no problems.

I tested the tap water and it was the same amount of high nitrates. But a week later it was ok.

Where was it OK - in the DT?

But still nitrates in the tap. I use an Aquatic Life four stage RO unit. All of the filters are new. I have changed over 100 gallons with RO water and this picture is the current nitrates.

Even if the Tap water have high concentrations - it should be 0 after a 4 sage RODI. What do you have in the RODI water? If you read any NO3 there - its either not working or you’ve mixed up the wastewater outlet with the clean water outlet!

Its right - you should read the colour from the top.

Sincerely Lasse

 

[mcarroll]

Why are you discussing corals and NO3 in this thread?

Why not? :D (<-- Toothy grin.....we may have gotten off the topic.....but the OP didn't say anything. LOL)

 

[Lasse]

Why not? :D (<-- Toothy grin.....we may have gotten off the topic.....but the OP didn't say anything. LOL)

Exactly he/she has not posted since the first post

Sincerely Lasse

 

[areefer01]

Just a small addition, since I know this could easily be misunderstood otherwise:

Once PO₄ is above 0.03ppm, the N:P ratio becomes much less critical. So this study doesn't really apply to most reef tanks. However, if you want to keep your tank below 0.03ppm PO₄, you might want to keep N low as well.

"In our experiments, a phosphate concentration of ~0.3 μM at a N:P ratio of 22:1 yielded an overall healthy phenotype. Accordingly, it is likely that the absolute N:P ratio becomes also less critical for the proper functioning of the symbionts when phosphate concentrations exceed a vital supply threshold (>0.3 μM), even when the symbionts are rapidly proliferating." (Rosset et al., 2017, §4.3)

0.3μM PO₄ ≈ 0.0285ppm PO₄ ≈ 0.03ppm PO₄​

Delbeek notes 50:1. Looking at his tanks data, health, and peer curators of public aquariums. Also noted a few studies on reefs while swapping corals between high and low nutrients.

 

[mcarroll]

Remind us what .3 µmoles is in ppm?

 

[Randy Holmes-Farley Verified Community Expert]

Remind us what .3 µmoles is in ppm?

0.3 uM phosphate is 95 g/mole x 0.3 umoles/L = 29 ug/l = 0.03 ppm

 

[EnterName]

Delbeek notes 50:1. Looking at his tanks data, health, and peer curators of public aquariums. Also noted a few studies on reefs while swapping corals between high and low nutrients.

I'm not sure I understood you correctly. Delbeek said a 50:1 N:P ratio worked for tanks? That sounds reasonable I suppose. Unfortunately we can't use the study to check it.

The study tested ratios of 117:1 and 211:1 (both bleached), as well as 22:1 and 1:60, which remained healthy. So nothing is really close enough to 50:1 to give us something to work with here .

We also can't tell the absolute P levels just from the ratio. So if the paper's assumption is correct that ratios don't really matter above 0.03ppm PO₄, we wouldn't be able to apply its findings anyway.

I think the following makes clear why I believe the paper correctly assumes that ratios don't matter too much above a certain PO₄ level anymore.
I calculated the "deadly" 117:1 N:P ratio for various phosphate levels. Nitrate levels above those stated in the table would bleach the corals if the N:P ratio still mattered at phosphate levels above 0.03ppm.

PO₄ (ppm)	NO₃ (ppm)
0.03	2.29
0.04	3.06
0.05	3.82
0.06	4.58
0.07	5.35
0.08	6.11
0.09	6.87
0.10	7.64

I don't think having 0.10ppm PO₄ and 10ppm NO₃ is causing corals to bleach and neither does 0.03ppm PO₄ and 5ppm NO₃ (at least not in my tank #AnecdotalEvidence).

There has to be something to the statement that at some point the ratios don't mean so much anymore in my opinion. Otherwise, many tanks would crash right now.

Edit: Obviously you can go so low with phosphate and/or nitrate that stuff dies. But that's not what the paper is about, and I don't think anyone is doubting that.

 

[Lasse]

Delbeek said a 50:1 N:P ratio worked for tanks? That sounds reasonable I suppose. Unfortunately we can't use the study to check it.

Sincerely Lasse

 

[EnterName]

Delbeek said a 50:1 N:P ratio worked for tanks? That sounds reasonable I suppose. Unfortunately we can't use the study to check it.

Sincerely Lasse

Thanks Lasse, that makes it clearer what he meant.

So the 50:1 refers to the N:P ratio in corals, bacteria and zooxanthellae. But as Delbeek says, this is different from the dissolved nutrient ratios to target.

The actual dissolved ratios he shows that might have caused the die-offs are also more extreme than those in the study.

I think it's fair to assume ratios don't lose all their meaning (if we ignore the visible instability of certain parameters in the presentation as potential causes). But if you need a ratio of 300:1 or higher to cause problems, that supports the paper's point that ratios become less critical with higher phosphate levels.

So I would say I'm torn because I still don't think the previously posted table shows deadly parameters. Randy's target ranges would also include deadly combinations otherwise.