Hey, i like to use just a little more than half of their recommended dose but you can use this method to either increase or deacrease your ppm, so here’s what i do: i use 45 gallons of RO water in my reservoir for my hydro setup, and i use a 2 gallon jug to mix my nutes in. First, i add 1.5 grams per gallon of Mg2SO4 to my res (magnesium sulphate, or epsom salts) and let that get good and mixed up while i do math and mix nutes. So, say I need 7.5 mls Micro // 2.5 mls Grow // 12 mls Bloom // 5 mls koolbloom all per gallon. So multiply by 45. 7.5 × 45 = 337.5 mls Micro // 2.5 × 45 = 112.5mls Grow, ect… put that in the 2 gallon jug, 1 nutrient at a time, mix it up, add the other, mix amd continue. Now that i have a 2 gallon jug of concentrated nutes mixed at the correct ratios, just slowly add it to the 45 gallon reservoir until you are at the desired PPM. Whatever nutes you have left over are already the perfect ratio to be used to top up your res as you grow. Happy growing.