# Re: Aquatic Plants Digest V3 #1377

Hello Steve,

You got it close (despite "pumpkin head" and all)!

I use a simpler calculation:

If one dissolves 36.6 g = 36,600 mg in 200 mL of water, the
concentration will be 36600 / 200 = 183 mg/mL.

Since NO3- is only 61% of KNO3, the concentration of NO3- will be 183 x
0.61 = 112 mg NO3- / liter.

Adding 1 mL of that solution to 100 liters of water would make it 1.12
mg/L or 1.12 ppm. But in a 100 L tank you will have only about 90 liters
of water, so your concentration will be 1.12 / .9 = 1.24 ppm -- close
enough!

Best,

George

> Date: Sun, 7 Nov 1999 17:35:46 -0600
> From: "Steve Bansee" <tvg at icenter_net>
> Subject: Chemistry Help.
>
> Hi all,
>
> I am trying to figure out how much KNO3 to add to my tank so I can get about
> 5ppm of NO3 but  chemistry is not that great.  I gonna write what I got so
> far, and if you all can tell me if I'm on the right track.
>
> 3 tablespoon KNO3 ~ 36.6g
> 200 ml water
>
> Concentration of KNO3 in 200ml water - 36600 / 0.2 = 180000ppm
>
> NO3 is 61% off KNO3.. so
>
> 180000 / 0.61 = 109800ppm of NO3 ....... right?
>
> so if I take 1ml off this solution and add it to my 100 liter tank,  What
> will I get?
>
> I can't seem to wrap my mind around the math on this one.
>
> is this close?
>
> (109800/1000) / 100l = 1.098 ppm
>
> Thanks
> Steve (whos head is big as a pumpkin right now)