Reef Chemistry Question of the Day #44 ppm-N units

[Randy Holmes-Farley]

Reef Chemistry Question of the Day #44

Wendy was doing her routine reef aquarium chores yesterday, and had just gotten a new nitrate kit. She got a result of 5 ppm-N.

"Hey Bill," she asked her boyfriend, "What are these units? Is this good or bad?"

"How should I know? I never heard of ppm-N before," he replied.

So the question is, how many ppm nitrate ion corresponds to a value of 5 ppm-N?

Good luck!
























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[Randy Holmes-Farley]

Anyone?

 

[leptang]

Parts per milllon-nitrates

 

[DFW]

5 ppm N X 4.43 = 22.15 ppm NO3. The nitrogen content of nitrate is 22.5% of the total weight of the molecule. (I found this on the internet.)

 

[beaslbob]

about 20ppm

4. +a scouch is the conversion factor

test kits aren't that sensitive anyway

 

[Randy Holmes-Farley]

test kits aren't that sensitive anyway

:lol:

 

[Randy Holmes-Farley]

And the answer is... 22 ppm nitrate ion. Very good.

This has more on the topic:

ppm-N (part per million nitrogen)
also known as ppm nitrate-N, ppm nitrite-N, ppm-ammonia-N


ppm-N is a way to measure nitrogen atoms in solution. It is equal to the ppm concentration of nitrogen atoms, and usually specifies what form they take. It is often used, for example, to describe the concentration of ammonia, nitrite, or nitrate ions in aquaria. It can also be used to describe the amount of nitrogen in dissolved organic matter (DOM), particulate organic matter (POM), or total organic matter (TOM) in seawater. In these cases, the results are reported as “nitrate = 12 ppm-N" or “12 ppm nitrate-N,” which means that there is 12 ppm of nitrogen in the solution is in the nitrate form. In order to convert ppm-N to ppm, divide the ppm-N value by the fraction of weight of nitrogen in the ion. The table below shows these corrections:


Species..................ppm-N....ppm
NH3 (ammonia).........1.00.....1.21
NH4+ (ammonium).....1.00.....1.29
NO2- (nitrite)...........1.00.....3.29
NO3- (nitrate)..........1.00.....4.43

from:

The Units of Measure of Reefkeeping by Randy Holmes-Farley - Reefkeeping.com

Happy Reefing.