<Dl> <Dd> LSI = pH (measured) − pHs </Dd> </Dl> <Dd> LSI = pH (measured) − pHs </Dd> <Ul> <Li> For LSI> 0, water is super saturated and tends to precipitate a scale layer of CaCO . </Li> <Li> For LSI = 0, water is saturated (in equilibrium) with CaCO . A scale layer of CaCO is neither precipitated nor dissolved . </Li> <Li> For LSI <0, water is under saturated and tends to dissolve solid CaCO . </Li> </Ul> <Li> For LSI> 0, water is super saturated and tends to precipitate a scale layer of CaCO . </Li>

What should the hardness of drinking water be