Owner`s manual

and total alkalinity act as buffers to stabilize the pH.
When they are properly adjusted, the pH will be stable
and easy to maintain. The pH is a measure of the
relative acidity and basicity of the water. The ideal pH
range is 7.2 - 7.8. When the pH falls below 7.2 the
water can become corrosive. Low pH can cause
damage to metal in the control system and heater,
excessive sanitizer consumption, and skin irritation. A
pH above 7.8 can be scale-forming and allow metals
or minerals in the water to form deposits and stain spa
surfaces.
Alkalinity
Alkalinity acts as a buffer to prevent the pH from
changing as other substances are added to the water.
Stability of the pH is directly related to the alkalinity. The
alkalinity should be between 80 - 140 ppm. Alkalinity
below 80 ppm makes it difficult to stabilize the pH.
Alkalinity above 140 ppm may increase the pH and
cause cloudy water, scaling, and decreased efficiency
of the sanitizer.
Note: Alkalinity & pH Increaser and Alkalinity & pH
Decreaser will affect both the pH and alkalinity.
Generally, smaller additions will change the pH and
have a very minor effect on the alkalinity. Larger
additions will also affect the pH, but will have a much
greater effect on the alkalinity. (Example: If the pH is
very high and the alkalinity is within range, adding a
few smaller doses of pH and alkalinity Decreaser
instead of one large dose will reduce the pH with little
effect on the alkalinity.)
Calcium Hardness
Do not use soft water in your spa. It is critical to have
calcium in your water and in most cases tap water is
fine. The ideal range of calcium is between 200 – 300
ppm. The calcium hardness is normally adjusted when
filling or refilling after draining the spa. High calcium
levels can cause scale buildup on spa surfaces and
equipment. Your spa can be protected against high
calcium by using Metal & Stain Remover per the
directions on the container. Low calcium levels can
cause spa water to become highly corrosive and
damaging to the equipment components and
plumbing. To raise calcium levels, use Calcium
Hardness Increaser. Most authorized dealers can test
the calcium hardness of your water.
marquis care and enjoyment guide
PAGE 50
MARQUIS SPAS