Question about ammonia complexes vs. ammonia-nitrogen

[jmaneyapanda]

So, in researching some info about photometers more, I have come into some info where literature indicates that these units will read the reagent values, but can be displayed in different "forms". For example, ammonia can be displayed in NH3, NH4, or NH3-N. I understand the mathematical differentiation between the three, being the the NH3-N reads only the nitrogen of that compound. But I dont understand which value I should be looking at. These matters are even worse for Nitrite. Reading a sample can yield a nitrite (NO2-) of 0.23, a nitrite sodium (NaNo2) of 0.35, or a No2-N of 0.07. These numbers are notably different. which one should be considered to understand the toxicity of the water?

again, I do understand that these are the same material, just being displayed in different forms, but how do I pick which form will give the accurate representation to our general toxic "ammonia", "nitrite", and "nitrate"?

[Randy Holmes-Farley]

They are mostly just units of measure, like centimeters and inches. You just need to know which you are using if you compare to any other persons units.

Ammonia can also be quoted as total ammonia or free ammonia. Again, focus on what they are being compared to , but I'd usually focus on total ammonia unless the pH is far from normal.

At RC, most of the time people quote values for nitrite ion, not nitrite-N.

These have more:

Ammonia and the Reef Aquarium
http://reefkeeping.com/issues/2007-02/rhf/index.php

Nitrite and the Reef Aquarium
http://reefkeeping.com/issues/2005-06/rhf/index.htm

The Units of Measure of Reefkeeping
http://reefkeeping.com/issues/2005-08/rhf/index.php

[jmaneyapanda]

They are mostly just units of measure, like centimeters and inches. You just need to know which you are using if you compare to any other persons units.

Ammonia can also be quoted as total ammonia or free ammonia. Again, focus on what they are being compared to , but I'd usually focus on total ammonia unless the pH is far from normal.

At RC, most of the time people quote values for nitrite ion, not nitrite-N.

These have more:

Ammonia and the Reef Aquarium
http://reefkeeping.com/issues/2007-02/rhf/index.php

Nitrite and the Reef Aquarium
http://reefkeeping.com/issues/2005-06/rhf/index.htm

The Units of Measure of Reefkeeping
http://reefkeeping.com/issues/2005-08/rhf/index.php

Thanks for the response. It was not so much for the comparison to anothers numbers, but instead as a comparison to zero. That being said, I typically cant find what actual form is being measured by most. They just call it ammonia, nitrite, and nitrate.

[Randy Holmes-Farley]

Except for ammonia, they are not "measuring" different forms. Just reporting in different units. As I said, like cm vs inches.

Total and free ammonia are different actual forms, related mathematically by the pH.

You can easily convert all of these to each other if you like, but almost no one at RC quotes ammonia, nitrite or nitrate nitrogen.

[jmaneyapanda]

I dont think Im making myself clear (as usual). :) If I were reading a sample for a tank, and the nitrite came up 0.23 mg/L No2-. I could switch forms, and it would be 0.07 mg/L no2-n. In trying to determine if this tank has condition that are completely acceptable (0.07) or on the precipice of concern (0.23), how do I assess this? Even in your reference from your Reefkeeping article, everything is merely stated in ppm. Not ppm No2- or PPM NO2-N. So the reference is very confusing. Does this make sense? I do understand that these figures are just conversions of the same value, but the reference point is where Im confused. In your cm vs inches analogy, we could say that I need something 10 inches from a mark. Or 25 cm from a mark. Both are the same. But how do I determine what to do is Im told it's "25" in length from a mark? I now length (PPM), and the value (25 nitrite), but the scale Im supposed to shooting for is vague. What sclae, in your article, are you referring to?

[Randy Holmes-Farley]

If I were reading a sample for a tank, and the nitrite came up 0.23 mg/L No2-. I could switch forms, and it would be 0.07 mg/L no2-n. In trying to determine if this tank has condition that are completely acceptable (0.07) or on the precipice of concern (0.23), how do I assess this?

You go back to whatever information you are using to determine if it is acceptable, and see what values in what units are acceptable, and which are not. 0 without any qualifiers is not anything that is recommended except by someone that is just repeating what they hear. So in my articles above, for example, I show what effects are known at what concentrations, and the units are clearly specified. For nitrite, I am quoting ppm nitrite ion, since there is no suggestion that it is otherwise by writing NO2-N or nitrite nitrogen.

In short, if it does not say “nitrogen” then it is total mass of the ion being named.

That said, neither nitrite value is a concern. Nitrite is almost never a concern in marine systems as it is quite nontoxic (despite people learning otherwise for freshwater systems and incorrectly carrying it over to marine systems). In any case, both those values are OK.

[jmaneyapanda]

OK, thanks. So any of the nitrogen readings (ammonia, nitrate, nitrite) are going to be in the non total nitrogen form, in your opinion?

By the way, those values I came up with were just arbitrary. I was just using them to demonstrate the ability for the different forms to have very different values, with scale gone.

[jmaneyapanda]

Let me re-phrase. Ammonia, for all intent purposes, should be read as NH3, not NH#-N. And likewise for Nitrite and nitrate, correct? It terms of generally accepted and used terms in this industry. Otherwise, such information would been specifically noted as NH3-N. I got this correct, right?

[Randy Holmes-Farley]

Any values posted here at RC and that do not state otherwise, yes. That is just the custom at RC, but it is also technically correct. Very few folks here ever give values in "nitrogen" unless there is a strong reason to (llike a measurement of organic nitrogen or some unusual thing that is not easily reported in other ways). :)

[jmaneyapanda]

Thank you very much. That answers what I needed to know.

[Randy Holmes-Farley]

You're welcome.

Happy Reefing. :)

[Boomer]

Panda

Just to make sure you see what Randy is saying here.


Example:

1 inch = 2.54 cm

25 C = 77 F

1 ppm NO3-N = 4.4 ppm NO3 (Nitrate ion)

In the NO3-N they are only looking at the ppm that the N will give. In the NO3 they are looking the ppm the N, and O's will give collectively, the right way. In either case the amount of N is the same. When the O's are added in the weight changes so the ppm value changes.

N = 14.007 grams MW

O =15.999 grams MW

So,
NO3

14.007N + ( 3 x 15.999 O) = 62.004



NO3-N

14.007N

So, the conversion is

62.004/ 14.007 = 4.4266

Thus as I said;

1 ppm NO3- N = 4.42 ppm NO3 (Nitrate)

The test kits are testing the same, it is only the unit of measurement being used that is different. It is like having two rulers 1 foot long, where one is marked in inches and the other it in cm but the length of the ruler at any point is still the same.

[jmaneyapanda]

Panda

Just to make sure you see what Randy is saying here.


Example:

1 inch = 2.54 cm

25 C = 77 F

1 ppm NO3-N = 4.4 ppm NO3 (Nitrate ion)

In the NO3-N they are only looking at the ppm that the N will give. In the NO3 they are looking the ppm the N, and O's will give collectively, the right way. In either case the amount of N is the same. When the O's are added in the weight changes so the ppm value changes.

N = 14.007 grams MW

O =15.999 grams MW

So,
NO3

14.007N + ( 3 x 15.999 O) = 62.004



NO3-N

14.007N

So, the conversion is

62.004/ 14.007 = 4.4266

Thus as I said;

1 ppm NO3- N = 4.42 ppm NO3 (Nitrate)

The test kits are testing the same, it is only the unit of measurement being used that is different. It is like having two rulers 1 foot long, where one is marked in inches and the other it in cm but the length of the ruler at any point is still the same.

Yes, I do understand this. My question was more alongs the lines of what if (for the sake of this example, and this example only), nitrate was toxic at 4 ppm (I know it's not. But, in measuring any random tank, the converted forms can be at or beyond toxic levels). But, in my whatif scenario, the toxicity of nitrate at 4 ppm in what form? Using your examples, the NO3-N is 1 ppm (safe), and the 4.42 ppm NO3 is toxic. So the form of the standard statement that 4 ppm is toxic is what I was questioning. Basically, what is the common nomenclature?

For example, we want ammonia minimized, right? As close to zero as possible. Well, how do I gauge a tanks stability when the ammonia levels can be expressed in two different forms? That was the basis of my question.

Using the ruler analogy, yes, both tool are the same length, but are delineated with different scales. How long is 8? Thats is the analogy I am asking. The "safe" values for these tests dont seem to indicate what form is being elucidated. Randy had stated that most all are stated in the ionized form, so that is what I was curious of.

[UVvis]

Very few folks here ever give values in "nitrogen" unless there is a strong reason to (llike a measurement of organic nitrogen or some unusual thing that is not easily reported in other ways). :)

I have to admit that this frustrates me to no end, and I believe it is ingrained to deeply for the aquarium industry to 'fix' their thinking, unfortunately.

The reason for ppm ion values probably goes back to the chemists developing methods for analysis. Then, for the aquarium type folk, we use these methods and just use the ppm values already established in the method because it was easy and already laid out before us. When in reality, we should have been wanting units in terms of biological reactions, not straight chemical analysis.

For most oceonographers and limnologists, they tend to favor the molar concentrations and 'Nitrogen as' values for this reason. It makes a straightforward and direct tracking method of the systems we are analyzing.

For example,

1 mole of Ammonia/ammonium becomes 1 mole of nitrite, which becomes 1 mole of nitrate. Done.

Or

1 gram of Ammonia-N becomes 1 gram of nitrite-N, which converts to 1 gram of nitrate-N. Easy.

Tracking the common denominator is easy. For some reason, we have collectively overcomplicated things.

Instead, we have a collective sillyness of reporting in ppm Ammonia, nitrite and nitrate. Then we have to convert values to find total inorganic N amounts, or nitrogen loading/cycling in a system.

Not meaning to go off on a rant, but I've never understood the reasoning behind using what I consider the wrong unit of measure for our intended application, aside from 'that is what the test reads in...'.
:hmm3:

[UVvis]

For example, we want ammonia minimized, right? As close to zero as possible. Well, how do I gauge a tanks stability when the ammonia levels can be expressed in two different forms? That was the basis of my question.

Using the ruler analogy, yes, both tool are the same length, but are delineated with different scales. How long is 8? Thats is the analogy I am asking. The "safe" values for these tests dont seem to indicate what form is being elucidated. Randy had stated that most all are stated in the ionized form, so that is what I was curious of.

Just to confirm, your question has been answered right?

[jmaneyapanda]

Just to confirm, your question has been answered right?


Yes, I was asking questions to elucidate my questions.......uh,......yeah, something like that!:p

Yes, I am all clear. Thank you all.

[jmaneyapanda]

I have to admit that this frustrates me to no end, and I believe it is ingrained to deeply for the aquarium industry to 'fix' their thinking, unfortunately.

The reason for ppm ion values probably goes back to the chemists developing methods for analysis. Then, for the aquarium type folk, we use these methods and just use the ppm values already established in the method because it was easy and already laid out before us. When in reality, we should have been wanting units in terms of biological reactions, not straight chemical analysis.

For most oceonographers and limnologists, they tend to favor the molar concentrations and 'Nitrogen as' values for this reason. It makes a straightforward and direct tracking method of the systems we are analyzing.

For example,

1 mole of Ammonia/ammonium becomes 1 mole of nitrite, which becomes 1 mole of nitrate. Done.

Or

1 gram of Ammonia-N becomes 1 gram of nitrite-N, which converts to 1 gram of nitrate-N. Easy.

Tracking the common denominator is easy. For some reason, we have collectively overcomplicated things.

Instead, we have a collective sillyness of reporting in ppm Ammonia, nitrite and nitrate. Then we have to convert values to find total inorganic N amounts, or nitrogen loading/cycling in a system.

Not meaning to go off on a rant, but I've never understood the reasoning behind using what I consider the wrong unit of measure for our intended application, aside from 'that is what the test reads in...'.
:hmm3:
This is the crux of my questioning. ANd the answer, it seems is "just because".

[Boomer]

Just to put down some history here. The Water/ Waste-Water/Pollution/ Professional Aquacultue Industry use only N values and always have. It was only this industry back in the 80's that started to switch to ion values. Some kits in this hobby are still as N values, HACH, Kordon, etc.., as where past kits from Marine Enterprises. And this is not the only thing in this hobby on water parameters that is this way. It is the same for Sg. Only in this hobby is Sg std @ 25 C, all other places are 15 C. When you tell an oceanographer we use a hydrometer calibrated to 25 C you get a funny look. I just look back and give them with a funny look and ask why 15 C when the max density of water is 4 C. And I can continue with the dumbest unit that is used in this hobby, Alk given as dKH or a worse unit grains /gallon. You would be amazed what grain / gal actually is and where it came from. Then there is another sick expression ppm as CaCO3. We just have to live with them all and adjust or convert to what " I " want to use.


Panda

Well, how do I gauge a tanks stability when the ammonia levels can be expressed in two different forms? That was the basis of my question.

This has always been an issue in this hobby and is why I always ask which form. The bad issue is many in this hobby just do not look to see what form. When doing searches on say Ammonia toxicity it is always give as N. However, there is not much of a big difference in Ammonia in either form as the conversion is only 1.2., i.e., 1 ppm Total Ammonia N= 1.2 Total Ammonia. When it comes to Ammonia one should not be looking at 1 ppm N vs 1.2 ppm or 2 ppm N vs 2.4 ppm. So, if Ammonia is anywhere near 1 ppm of either form you need to get very concerned. In this hobby there is little worry about Nitrite, due to the protection of the Cl- Mg++ and Ca++ ions against Nitrite Toxicity. FW is another issue. Nitrate is also of little worry in fish tanks but is a different issue in reef tanks. This is about the only one. Thinking you have say 10 ppm Nitrate and one then tells you it is really 44 ppm is a huge difference or 1 ppm vs 4.4 ppm.

[UVvis]

Just to put down some history here. The Water/ Waste-Water/Pollution/ Professional Aquacultue Industry use only N values and always have. It was only this industry back in the 80's that started to switch to ion values. Some kits in this hobby are still as N values, HACH, Kordon, etc.., as where past kits from Marine Enterprises. And this is not the only thing in this hobby on water parameters that is this way. It is the same for Sg. Only in this hobby is Sg std @ 25 C, all other places are 15 C. When you tell an oceanographer we use a hydrometer calibrated to 25 C you get a funny look. I just look back and give them with a funny look and ask why 15 C when the max density of water is 4 C. And I can continue with the dumbest unit that is used in this hobby, Alk given as dKH or a worse unit grains /gallon. You would be amazed what grain / gal actually is and where it came from. Then there is another sick expression ppm as CaCO3. We just have to live with them all and adjust or convert to what " I " want to use.


Ha... Grains are an odd unit of measure in the first place...

Speed limits should be changed over to rods/pie*deciseconds.

Then again, I've turned microcuries into banana equivalency units to explain levels of radiation before. I felt awful for that one...