Re: Nitrates

[Chuck H <grendel at usit_net>]

Shireen quizzed:

> What is your definition of the word "nitrate" as printed
> on the instruction sheets of nitrate test kits?
>
> Multiple choice version:
> Nitrate is
>    A) NO3
>    B) NO3-N (nitrate nitrogen)
>
> Essay version:
> what does NO3-N mean?
>
> It would be useful to add the definitions of NO3 and NO3-N to
> some FAQs, and explain somewhere that when people commonly
> talk about nitrates, or refer to it as NO3, they're really talking about
> NO3-N. It's a very confusing issue.


The shorthand for nitrate is NO3.  That means it's made of one element of 
nitrogen (N) and three elements of oxygen (O).  If you want to get 
technical with it, you can add a minus sign to the end (NO3-) to represent 
the overall negative electrical charge nitrate has.  When folks talk about 
nitrate, NO3 is what they are referring to.

Nitrate-nitrogen (NO3-N) is basically just a way of saying "nitrogen that 
comes from nitrate."  In other words, it just refers to the nitrogen part 
of the nitrate molecule.  A value for ppm nitrate-nitrogen can be converted 
to ppm nitrate by multiplying by 4.4.  For example, my Hach test kit gives 
results as nitrate-nitrogen.  Earlier today, I tested one of my tanks and 
the reading was 0.8ppm nitrate-nitrogen.  That means that the tank 
contained 3.5ppm nitrate (0.8 x 4.4 = 3.5).  The familiar guideline of 5 to 
10ppm nitrate is the equivalent of 1.14 to 2.27ppm nitrate-nitrogen.

Hope it helps.
--
Chuck Huffine
Knoxville, Tennessee