Spa Water Balance

To keep your spa water comfortable and inviting, be sure to adjust the spa water balance as needed.  Balanced spa water is the best way to ensure that bathers are comfortable and the water is clear and ready to use.  Balancing spa water includes adjusting levels of pH, alkalinity and calcium hardness to their proper range.

pH Scale


pH is a scale that runs from 0 to 14 and measures how acidic (low pH) or basic (high pH) something is, in this case spa water.  The correct pH range for spa water is 7.2 - 7.6 or just about in the middle of the pH scale.  Proper pH makes the spa water feel comfortable and helps protect equipment and surfaces from damage.  Keeping the water in the proper pH range also helps the Spa Essentials® products work their best.

If the pH is too high (above 7.6) sanitizers are less effective, surfaces and equipment can scale, water may cloud, and shorter filter runs may occur.  Correct this by adding Spa Essentials pH Decreaser.  Low pH (below 7.2) causes sanitizers to dissipate more rapidly, increases corrosion of surfaces and equipment, and may make water irritating to spa users.  Adjust low pH by adding Spa Essentials pH Increaser.  Maintain pH level between 7.2 - 7.6.


Alkalinity is a measure of the water's buffering capacity or ability to resist changes in pH.  The proper alkalinity range for spa water is 125 - 150 parts per million (ppm).

Keeping the alkalinity in its proper range will prevent the pH level from moving too high or too low.  If the alkalinity is too low, add Spa Essentials Alkalinity Increaser.  If the alkalinity is too high use Spa Essentials pH Decreaser.

Calcium Hardness

The calcium hardness level in spa water also needs to be adjusted to its proper range.  Low levels of calcium (water is too soft) can lead to corrosion of equipment and staining of surfaces.  Add Spa Essentials Calcium Hardness Increaser to raise low calcium hardness.  High levels of calcium can cause scaling of equipment (reducing efficiency) and ugly, rough patches on the interior of the spa.  Calcium hardness should be maintained between 100 - 200 ppm.  Use Spa Essentials Stain & Scale Control if calcium hardness is above 200 ppm.

Proper Water Balance Ranges


pH 7.2 - 7.6
Alkalinity  125 - 150 ppm
Calcium Hardness  100 - 200 ppm