Question: what is the formula to calculate total hardness?
Answer: The total hardness is determined by the sum of Ca and Mg: TH = (2×1.40 + 2×0.23) meq/L = 3.26 meq/L – as presented in the diagram above. We use the same example water C1. sol and add 2 mM NaOH (with button Reac) 2. Here the difference is given by the pseudo hardness: PsH = 1.19 meq/L.