Hm, so I used the calculator to calculate a solution of k2SO4 in 30ml doses in a 1000ml container for a 75 gallon tank.
EI here states 1/4 tsp 3 times a week. Calculator says....
To reach your target of 8.5ppm K, you'll need to add 179.259 grams of K2SO4 into your 1000.0 mL container.
Each 30.0 mL of that mix into 75.0 gal is:
179.259 grams = 12.1229358 US tablespoons
I'm dosing twice as much k2SO4 versus KNO3? huh? (I had around 6.2 TBSP for my tank).
I feel it should be more like 1.6 tablespoons...