Total Hardness refers to the amount of calcium, magnesium, carbonate and other mineral salts in the water.

Low Calcium Hardness can lead to corrosion of equipment and staining of surfaces.  High levels of calcium cause scaling of equipment, thus reducing its efficiency and may lead to cloudy water.

The ideal range for Calcium Hardness is 120 – 500 mg/litre. Calcium Hardness should be tested on first filling the hot tub, and thereafter at monthly intervals.

To raise Calcium Hardness, add Calcium Chloride in accordance with supplier’s instructions.

Lowering Calcium Hardness can only be achieved by dilution with fill water at a lower Calcium Hardness concentration.  As water evaporates from the hot tub, the minerals stay behind and become more and more concentrated. This will lead to cloudy water, scale formation and eye irritation. In most cases, make up water has the effect of diluting this concentration to a point where it is of little concern. In a hard water area, it may be necessary to use a binding or Sequestering agent to prevent precipitation of solids.

In contrast, water with low Calcium Hardness (soft water) can be very corrosive and can cause serious damage to the hot tub equipment and plumbing.  Softened water must NOT be used to fill a hot tub.

Please read instructions on the products before use.