My water is about 140 ppm @ 7.5 pH coming out of the tap, so I add enough Calcium to bring it up to 300 ppm then adj nutes for approx 1000 ppm/5.5 - 5.9 pH. When rooting and early veg, they seem to do better on the acidic end around 5.3 to 5.5 pH then around 5.5 to 5.8 pH for bloom...