Nitrate

[JonasRoman]

So, a common subject, still needed to discuss as its something that surround the coral 24/7 and of our concern.
We had a thread recently where I posted an article about the negative metabolic effects of hign temp and high (0.19 so not ao high) nitrate together, and also the opposite beneficial effect of ammonium.
The discussion is relevent, is nitrate a problem also in normal temp or just when coral is getting stressed?

Since decades we have struggled getting nitrate down and invented nitrate reactors, carbon source method (vodka method) etc. We see nitrate as a pollutant, as its a waste product of the nitrification and insufficiently denitrification. Denitrification is always more hard to get a good turnover as it need anareobic areas which is harder to get than aerobic surfaces ofcourse.

So I think most aquarist agree we do not ignore a raising nitrate. But, where is the limit and how much concern should it make? We have a lot of examples of tanks that look fine with high nitrate. That can be because of adaptation, some corals have died so you now have a selection , and some corals genetically are less sensitive to nitrate .

I found another study(they are refereing to the previous one), with a different design from the other we have discussed, where they have compared a corals metabolic response in high temp (30 gr) versus normal (26 gr) with and without increased nitrate, AND also compared to ONLY high temp.

The interesting finding in this study is:The coral did NOT respond badly to solely high temp 30, but when you added nitrate(0.56 ppm NO3) to that it responded badly: reduced photosynthesis efficiency, increased risk of thermal bleaching, and decreased bacterial diversity. This was already at nitrate levels we consider low. With even lower nitrate (0.15 mg/l) similar findings but not so severe. (That resembles the study from 2021). Note also that the stress symptoms developed already after 2 days with a culmen day 14. There was no PO4 limitations.

In the era of zeovite, we discussed ultra low nutrition, and many with me was against that. I am still that. BUT what we didnt understand at that era was that it was probably the low PO4 that was the issue, not the low nitrate. Some of us dosed nitrate as we where scared. I think that was a great misunderstanding as we didnt know better.
Today, I am afraid of low PO4, and high nitrate.

My own tank: PO4 AND NO3 is raising last months, a lot of fishes. I will introduce one more deni-block, but so far do not open the GFO box as long as I am below 0.1 in PO4.

This field has really developed, and when people say its ok with 25 ppm in nitrate I just wonder if they have something more substantial than just "I have seen tanks with that and it looks good". Its a very weak argument, and I will say those choose to ignore these interesting data, even if its not 100% proven, its hard to deny these beatiful studies.

https://www.sciencedirect.com/science/article/abs/pii/S0141113625001552


Jonas

 

[Garf]

30C is very warm for a tank. Don't have access to see if the negatives suddenly start at 30C or if they start lower, then ramp up. I expect if the negatives appear below 30C, they would have made a song and dance out of it.

 

[JonasRoman]

30C is very warm for a tank. Don't have access to see if the negatives suddenly start at 30C or if they start lower, then ramp up. I expect if the negatives appear below 30C, they would have made a song and dance out of it.

The test is 26 and 30. No ramp up. 30 degree with NO nitrate addition did not lead to negative responses. Thats interesting.

The scientists do this experiment as their hypothesis is that increased nitrate in ocean due to environmental changes may contribute to bleaching. The interesting differences from 2021 study I think is that they tested with only thermal stress aswell and found no neg effects until nitrate also was added.

 

[CHSUB]

You are going to have a hard time convincing this group no3 is better low than high, however continue your efforts. Most have not been around long enough to know any better. I have witnessed both ends of the scale. In the past many reefs suffered with high no3 using trickle type and undergravel filters. Then Sprung published a “better way” in his reef books. Imo, carbon dosing pushed no3 below natural levels and currently we are in a “push back” period.
I think at some point the hobby will rediscover no3 at 0.5 ppm is ideal, easily maintained, and still many times higher than natural levels. At that value the hobbyist will simply concentrate on more important parameters.

 

[JonasRoman]

You are going to have a hard time convincing this group no3 is better low than high, however continue your efforts. Most have not been around long enough to know any better. I have witnessed both ends of the scale. In the past many reefs suffered with high no3 using trickle type and undergravel filters. Then Sprung published a “better way” in his reef books. Imo, carbon dosing pushed no3 below natural levels and currently we are in a “push back” period.
I think at some point the hobby will rediscover no3 at 0.5 ppm is ideal, easily maintained, and still many times higher than natural levels. At that value the hobbyist will simply concentrate on more important parameters.

I am not interested in convincing anyone. The study is for all and interpretation are free, and speaks for itself
Yes, I believe same as you.

 

[Randy Holmes-Farley Verified Community Expert]

This field has really developed, and when people say its ok with 25 ppm in nitrate I just wonder if they have something more substantial than just "I have seen tanks with that and it looks good". Its a very weak argument, and I will say those choose to ignore these interesting data, even if its not 100% proven, its hard to deny these beatiful studies.

How is it weak to show real examples? Seems weaker to me to ignore real reef tanks and point to artificial scientific studies that show a stress to one or two species of coral from nitrate, and conclude its a problem for real reef tanks.

Maybe it is a stress, and maybe that stress is really not that important to a real reef tank at ordinary temperature, adequate phosphate, etc.

Example tanks with 100 ppm nitrate that anyone would be envious of seem extremely convincing to me. Richard Ross' tank with 1 ppm phosphate and 100 ppm phosphate, for example.


from it:

Randy’s Thoughts on Nutrient Target Ranges​

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/


Figure 1. A very high nutrient system maintained by Richard Ross, with nitrate sometimes above 100 ppm and phosphate above 1 ppm. Details in this link:
https://www.reef2reef.com/threads/rich-ross-home-tank-guess-the-phosphate.296635/

 

[Randy Holmes-Farley Verified Community Expert]

You are going to have a hard time convincing this group no3 is better low than high, however continue your efforts. Most have not been around long enough to know any better. I have witnessed both ends of the scale. In the past many reefs suffered with high no3 using trickle type and undergravel filters. Then Sprung published a “better way” in his reef books. Imo, carbon dosing pushed no3 below natural levels and currently we are in a “push back” period.
I think at some point the hobby will rediscover no3 at 0.5 ppm is ideal, easily maintained, and still many times higher than natural levels. At that value the hobbyist will simply concentrate on more important parameters.

IMO, the issue is not only what is "best', but what exactly bad happens with higher than "optimal" nitrate.

If the answer is really little to nothing that an aquarist can observe in the tank, then this is just a nonissue.

So I'll turn it back to you and Jonas:

What observable problem (not a hypothetical stress problem) happens when average Joe keeps his reef tank with 50 ppm nitrate?

 

[JonasRoman]

How is it weak to show real examples? Seems weaker to me to ignore real reef tanks and point to artificial scientific studies that show a stress to one or two species of coral from nitrate, and conclude its a problem for real reef tanks.

Maybe it is a stress, and maybe that stress is really not that important to a real reef tank at ordinary temperature, adequate phosphate, etc.

I think you are right that its a stress, but the impact of that will ofcourse vary. I mean, the study says same, "nitrate only" did not cause any harm, it was together. But that says that if high nitrate we have loosen a security belt. With no security belt you can still drive the car without ending in a hospital if nothing more bad happens.

Also, from which perspective is the responsibility of evidense, that phalang that believes in unnatural levels is ok or that that believes in mimic natural levels? I think he proof of burden is more on the "nitrate group" than opposite to be honest.

 

[JonasRoman]

What observable problem (not a hypothetical stress problem) happens when average Joe keeps his reef tank with 50 ppm nitrate?

If not any other stress factors, maybe nothing (but we dont know as we dont know how the tank would look like if nitrate was lower, and we dont know if maybe some coral that died maybe would have survived, we only knows that those you see are ok), but if another stressfactor appears, we have lost a security belt. Why take the risk?? Turn around the question to you Randy:What is the bad thing with run this beatiful tank at nitrate 5 ish to be sure??

 

[JonasRoman]

Just one note that touch this subject. We are all changing our minds depending on new knowledge, studies and experience. For PO4 I admit I have changed my view of this dramaticaly thanks to good input from here, and studies that have convinced me. I cant see the necessary to have ecxess of it, but definitely very crucial to not have deficiency.
Actually, today my PO4 is 0.09, has been risen slowly since more fishes and heavy feeding. Back in the days I would use GFO now, but I will not, and just observe. And will definitely dose Po4 if I some day measure 0.00 (that will not happen though with all my fishes....)

 

[Randy Holmes-Farley Verified Community Expert]

Also, from which perspective is the responsibility of evidense, that phalang that believes in unnatural levels is ok or that that believes in mimic natural levels? I think he proof of burden is more on the "nitrate group" than opposite to be honest.

I agree that if one suggests unnatural levels are OK, that the burden is on the unnatural levels to show it works. That said, we have unnatural levels of many things, potentially including particulate N and P in tanks with low nitrate. Maybe those have unnaturally low total available N.

IMO, one cannot argue that it is clear from examples such as I posted, that it is possible to have a great tank at high nitrate. Further, when Richard lower nitrate and phosphate, he specifically said he noted no big changes.

Itis also possible to have great tanks with low nitrate. I'm not saying that is necessarily a problem, because there are many sources of N.

Since I have shown an example of a real reef tank with high nitrate and that is great by most standards, should not be the burden be on those that say it is bad to clearly state what "problem" will arise, and show evidence that it does?

 

[Randy Holmes-Farley Verified Community Expert]

Just one note that touch this subject. We are all changing our minds depending on new knowledge, studies and experience. For PO4 I admit I have changed my view of this dramaticaly thanks to good input from here, and studies that have convinced me. I cant see the necessary to have ecxess of it, but definitely very crucial to not have deficiency.
Actually, today my PO4 is 0.09, has been risen slowly since more fishes and heavy feeding. Back in the days I would use GFO now, but I will not, and just observe. And will definitely dose Po4 if I some day measure 0.00 (that will not happen though with all my fishes....)

I too have changed my mind over the years on phosphate. :)

 

[Randy Holmes-Farley Verified Community Expert]

Turn around the question to you Randy:What is the bad thing with run this beatiful tank at nitrate 5 ish to be sure??

Since my recommended nitrate level is 5-50 ppm, I conclude nothing bad will result. I do not think higher nitrate than 5 ppm is needed. I just question the problems that arise if one goes higher. :)

At lower levels, one puts more burden of N availability on urea, ammonia, and organics (dissolved and particulate). Those may well all take up the slack in many/most reef tanks, but not, IMO, in all, and one generally would not know that in advance before seeing that there is a problem.

 

[JonasRoman]

Since my recommended nitrate level is 5-50 ppm, I conclude nothing bad will result. I do not think higher nitrate than 5 ppm is needed. I just question the problems that arise if one goes higher. :)

At lower levels, one puts more burden of N availability on urea, ammonia, and organics (dissolved and particulate). Those may well all take up the slack in many/most reef tanks, but not, IMO, in all, and one generally would not know that in advance before seeing that there is a problem.

I understand and it sound logic to see nitrate as a secondary indication that we have ammonium enough, or vice versa, if nitrat is low we are afraid of also having low ammonium.

In my system I have heavy input of food but still "low" NO3 (today 4 ppm ish). I think its very interesting to see how much of my total N is in form of ammonium, so maybe send a N-DOC to triton.

Havent triton a recommended N/NO3 ratio? Do you remember their recommendations? (I can check)

Jonas

 

[JonasRoman]

Ok I found it. The so called "triton ratio" they (Triton) say "Total N"/NO3 ratio shall be ideally 1:3. It sounds very much to the NO3 side. I cant see any evidence or how they have established this ratio. Their website contains a lot of words but not so much information.
Anyone knows? @Randy Holmes-Farley ?

Jonas

 

[Randy Holmes-Farley Verified Community Expert]

Ok I found it. The so called "triton ratio" they (Triton) say "Total N"/NO3 ratio shall be ideally 1:3. It sounds very much to the NO3 side. I cant see any evidence or how they have established this ratio. Their website contains a lot of words but not so much information.
Anyone knows? @Randy Holmes-Farley ?

Jonas

No idea why they elected that.

 

[CHSUB]

IMO, the issue is not only what is "best', but what exactly bad happens with higher than "optimal" nitrate.

If the answer is really little to nothing that an aquarist can observe in the tank, then this is just a nonissue.

So I'll turn it back to you and Jonas:

What observable problem (not a hypothetical stress problem) happens when average Joe keeps his reef tank with 50 ppm nitrate?

50 ppm no3 is really high for me, I can’t even rap my head around a level that high. Similarly I have difficulty understanding what happens at the Event Horizon of a black hole, both are “foreign” concepts for me….
So I will use your lower recommendation of 5 ppm no3 and believe the average Joe will be fine with that level. Personally I like to mimic a natural reef with nearly everything, so my
tank is designed after this picture to include natural parameters… just because.