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Re: ANitrate test kits

>From: Michael Rubin <michael at rubinworld_com>
>Subject: Nitrate test kits
>I fully blame Steve Dixon for getting me interested in adding KNO3 to my 
>tank as part of my water changing and dosing routine.  His gorgeous 
>aquaria, on display at last week's SFBAAPS meeting, were just cooking away 
>on the stuff.
>The difficulty is measuring total N ppm. 

Michael, Don't go out to buy the N (or NO3) test kit so fast! First do a
quick test to see if your tank is nitrogen limited. If you add a small
amount (say, 1/8 teaspoon --see below), and the plants don't start to
bubble like Steve's [or like Dave G's or like Jeff K's or like Tom B's or
........] then your tank is either not deficient in nitrogen or may be
lacking something else (like another macronutrient, including carbon, or
some trace elements or may need more light to generate enough O2 or...). If
you have visible algae, then your tank is probably not low in N. I
discovered a long time ago (pre-PMDD) that I had to add nitrates when the
plant groth slowed. When a tank is limited, there will be other signs --
like languishing duckweed. Duckweed is a good indicator plant and is
cheaper than a test kit. [Of course, there are other advantages to adding N
and or K even after the plants are bubbling. When this is done, -- together
with extra trace elements, light and CO2 -- photosynthesis will be
accelerated, more water borne Phosphates will be consumed and algae will
eventually diminish. This will result in nice algae free plants which we
saw over at Steve's.]

    concentrations resulting from small additions of chemicals
Compound	       ion  or  	percent (p)		concentration (ppm) 
		       element	of compound 	resulting from
								1 g in 50 gal (189 L)
Sodium Nitrate	  nitrate		73			3.9
(Nitrate of Soda)	  nitrate N		16			0.9
NaNO3		  	  sodium		27			1.4

Potassium Nitrate		  potassium		39			2.1
KNO3				  nitrate		61			3.2
N				  Nitrogen        14                0.7


Compound		Weight (g) 		Element	Concentration (ppm)
			per 1/4 tsp.	or ion	of 1/4 t in 50 gallons
sodium nitrate		1.8       	NO3-			7.0
                                    N+                1.5

Potassium nitrate 	1.4   	K+			2.9
     						NO3-			4.5
                                    N+                1.0 
from my article which is somewhere in the KRIB