Significance of Water Hardness Testing

Swimmer

Proper chemical balance in a pool or hot tub is imperative for both the enjoyment of the swimmers and for general maintenance. The significance of water hardness testing is to determine the calcium and magnesium levels in the water.

Too High

Too much calcium and magnesium can result in a scaly buildup on the sides of the pool and eventually plug the piping, pump and other equipment. It can also lead to eye irritation in the swimmers.

Too Low

Too low hardness levels can result in scarring and pitting of the pool surface and corrosion in the equipment, such as the pump and piping.

Recommended Level

The hardness test should result in a measurement of at least 200 ppm but no more than 400.

Resolution

If the level is too low, add calcium chloride. If the level is too high, remove some of the water and add fresh. Don't forget to retest afterward.

Other Applications

Water hardness tests are also run on drinking water. Water with a hardness of 120 ppm and up is considered hard water when it comes to consumption.

References

• Michigan State University: Pool Water Testing
• Water Research: Hardness