# Dosing KNO3



## Left C (Nov 15, 2003)

Chuck has a simple to use fert calculator to make solutions like you want: http://csd.net/~cgadd/aqua/art_plant_dosage_calc.htm

The fertilator calculates the amount of NO3 and K in KNO3 whereas Chuck's calculator only calculates the NO3. (You can calculate the amount of K in a KNO3 dose. You multiply the ppm of NO3 by 0.63 to get the K level.)

from the fertilator: 0.895 grams in 29* gal of water = 5.00 ppm of NO3 and 3.15 ppm K (0.900 grams is 5.03 ppm NO3 and 3.17 ppm K)

* You might want to enter 25 gal instead of 29 gal in the calculators because this approximates the actual amount of water.

These two calculator should fix you up.


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## McGornel (Aug 3, 2009)

That's the calculator I was using. He says the recommended target for K is 15-20 ppm, and trying to keep the NO3 down around 5 while trying to reach that level is near impossible? Am I just missing something? Or is that extra NO3 to reach the required K not going to be a problem?


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## OverStocked (May 26, 2007)

You should use KNO3 for nitrate, and other sources for potassium. KNO3 should not be your only fertilizer. Chucks page give pretty good directions. All of the macros we use have K in them.


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## plantbrain (Dec 15, 2003)

McGornel said:


> That's the calculator I was using. He says the recommended target for K is 15-20 ppm, and trying to keep the NO3 down around 5 while trying to reach that level is near impossible? Am I just missing something? Or is that extra NO3 to reach the required K not going to be a problem?


The advice is a bit dated and the cal is still there, but the advice should be modified.

I'd say 10-30ppm is a better target for NO3.
20-30ppm or thereabouts for K+, does not matter that much.

Above these are fine as well, but you are not getting much benefit from it.
Below, you can run into limiting levels of nutrients in some cases. 

Light/CO2 are more important to consider.
Focus obsessive compulsive there, not with nutrients, add them/dose, be done with it.

Regards, 
Tom Barr


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## Diana (Jan 14, 2010)

My tanks seem to run to so much NO3 already that I do not need to dose much. Similar about the PO4. 
The amount of K that I get when I dose the proper levels of these for N and P is so little that I do not count it as a real source of K. 

I use K2SO4 for potassium, and I dose a lot of it. My test: The plants do not have holes in the leaves when there is enough K in the tank.


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## fitness2go (Oct 13, 2005)

How much K2SO4 for a low light 15 watt on for 8 hours over a 10 gallon soft water tank (150 TDS) CRS tank, with no ferts and no CO2, but stuffed with moss, anubias nana petite and java fern 'Philippine'? I was thinking of starting off with a Smidgen 1-2x per week.

David


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