# NO3- vs Nitrate-Nitrogen



## mistergreen (Dec 9, 2006)

nitrate = NO3

lamotte & tetra probably use different chemicals to test for no3, hence the different in readings.


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## Left C (Nov 15, 2003)

The atomic weight of N is 14.01 and the atomic weight of NO3 is 62.01. 

NO3 is 4.4 times heavier than N. This is why there is a conversion.


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## KevinC (May 24, 2004)

Left C said:


> The atomic weight of N is 14.01 and the atomic weight of NO3 is 62.01.
> 
> NO3 is 4.4 times heavier than N. This is why there is a conversion.


A little more to clarify:

ppm in freshwater is really milligrams of something per liter of water. So if you are talking about 1 milligram of nitrogen in the form of nitrate (NO3~N), then the total mass of nitrate is actually 4.4milligrams (given the above relationship).

The types of chemicals doesn't matter - this is like using degrees-F versus degrees-C (though that conversion is slightly more complex).


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## jjp2 (May 24, 2008)

KevinC said:


> The types of chemicals doesn't matter - this is like using degrees-F versus degrees-C (though that conversion is slightly more complex).


This was what I was wondering. 

Sometimes there is a difference or importance with subtleties so just wanted to see if this was one that I needed to be concerned over or not.

Thanks,


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