According to the calculator, if I add 1 tablespoon of KNO3 to a 90 gal tank, I would be dosing 20 ppm of Potassium w/c is the right amount ,but I'd be putting in 30.2 ppm of Nitrate and the required amount for Nitrate is only 5 ppm. Is this alright or its better to dose KH2SO4 instead for Potassium?