What is calcium hardness?

Low hardness can corrode the heater and damage the spa surface, as well as contribute to excessive foaming. High hardness can cause scale buildup and cloudy water. The higher water temperature of a spa makes it more difficult for calcium to stay in solution, so it is recommended that Stain and Scale Control be used weekly to prevent any scale buildup.

If a water softener was used when filling the spa, replace the calcium as soon as possible. Softeners eliminate calcium from the water and can cause equipment damage and surface corrosion. Follow label or computer recommendations for amount of Calcium Hardness Increaser.