Calculation help needed

[tubamanandy]

Struggling with some of the online calculators.

I've made a 1ltr solution using 5 grams of KNO3 - how much of this solution do I need to add to a 90 litre
tank to get Nitrate levels of 10ppm ?

 

[dw1305]

Hi all,
You need to work out the percentage of NO3 in KNO3, For this you need the RAM of the elements, K = 39, N = 14 and O = 16. 39 + (14+ (16*3)) = RMM 101, of which NO3 is 62, so ~62%.

You need to multiply 5 by 0.61, which means that you have ~3.1g NO3 in 5g KNO3.

3.1g = 3100 mg in 1 litre, and mg/l is equivalent to ppm. If you divide 3100/90 you get ~34.5. So if you add your 1 litre of KNO3 solution you have added about 34.5 ppm NO3 to your 90 litre tank. If you divide that by ~3 1/3 you get ~10ppm. So approx. 300ml of your solution will add ~10 ppm NO3.

cheers Darrel

 

[tubamanandy]

Thanks Darrel !!!!