What Should Pool Calcium Hardness Be?

Calcium hardness is related to the same ‘water hardness’ that can cause scale in sinks and showers. Below hardness levels of 200 ppm (i.e. water too soft), pool water can become corrosive to fittings, fixtures, grout, etc. Above 400 ppm (water too hard), water may become cloudy, or scale can form around the pool and liner. Check and adjust calcium hardness after confirming the alkalinity of the water.

NOTE: The occurrence of scaling may be the result of other factors. If seeing scaling on a pool within the normal calcium hardness range, contact your dealer. Maintaining proper calcium hardness levels in a pool prevents corrosion, scale buildup, and cloudy water.