how do you lower hardness in pool water?
How to Reduce Pool Water Hardness & Alkalinity Reduce Pool Water Hardness. 1  Take a water sample from a depth of at least 12 inches from the water surface. 2  Add a reagent from a hardness test kit to the water sample and check the result against the guide provided by the test kit manufacturer. 3  Drain some of the water in the pool if the water hardness level is too high.