Calcium Chloride and Pool Care

Calcium hardness is an important aspect of pool care.

Calcium hardness is an important aspect of pool chemistry. If calcium hardness ranges too high or low, it can affect water quality and pool condition. Adding calcium chloride can boost calcium hardness if it drops too low.

Features

Calcium hardness measures the concentration of dissolved calcium salts in the water. Unusually high or low values are seldom a problem if the pool is well-maintained; nonetheless, you should always check calcium levels as part of your pool maintenance. Optimal levels are between 250 and 350 parts per million (ppm).

Low Values

If calcium hardness is too low, the water in your pool may leach calcium from the pool walls and cause gradual deterioration. To avoid this, add calcium chloride. As a rule of thumb, add 2 ounces per thousand gallons of pool water to raise calcium hardness by 10 ppm.

Considerations

Avoid adding too much calcium; excess calcium hardness can cause scale formation, clogging pipes and filters and irritating swimmers' eyes. Measure calcium hardness both before and after adding calcium chloride.

References

• Pool Wizard: Calcium Hardness
• North Carolina Department of Environmental Health: Water Chemistry for Swimming Pools