How much baking soda?
I'd like to raise the KH in my 10gal to 7dKH, but I'm not sure how much baking soda to add. Actually, I know exactly how much to add, but I'm not sure which KH reading to base the calculations off of. The specs from the city water supply say the KH is 64ppm, or 3.6dKH. In that case, I'd have to add 0.68 tsp. My KH test says the water is 4dGK, which would require 0.6 tsp to reach 7dKH. Which numbers should I go off of? I'd like to stick with the city's numbers, but after going through the pipes and whatnot, I'm not sure if that will alter the numbers from the treatment facility.