LaMotte Pool & Spa Owner's Handbook - Manual (Page 13)

TOTAL HARDNESS
Total hardness refers to the level of dissolved calcium and magnesium
in the water. The most common contributor of hardness is from the source
water used to fill or top off the pool or spa. Other sources include forms of
chlorine, such as calcium hypochlorite, and the intentional addition of
calcium chloride. Owners of plaster pools should make concerted efforts to
avoid low hardness levels especially when opening a new pool. Water is
naturally, a “universal solvent” and if the hardness level is too low, the
plaster can be rapidly dissolved from the pool walls. In other types of pools
or spas it is important to keep hardness levels within adequate ranges in
order to prevent etching or dissolving other hardware components, such as
heaters and plumbing.
If the hardness level is too high, the water can become cloudy and scale
may form on pool surfaces and equipment. Scale will appear as small white
deposits at the water level on walls, ladders, and numerous other places
that the owner may not see. If left uncorrected, scale can clog pipes and
filters, as well as damage heaters.
Fortunately, there is a point where water is not corrosive or scale forming.
By keeping the hardness, alkalinity and pH factors within their ideal
ranges, the water is balanced and the pool or spa will provide many years
of trouble-free use.
When using the 5-way strip, read pad 5 (near the handle) to determine
the total hardness level. Note: this pad is the last to be viewed so allow
10-15 seconds after dipping before reading the result. If hardness is too
high, the best option is to dilute it with fresh water that is low in hardness.
If the hardness level is too low, add calcium chloride to the pool or spa as
recommended in the treatment tables in the back of this book. Carefully
read the precautions for use since mixing calcium chloride and water in a
bucket can generate a very warm solution.
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The ideal total hardness range for pools is
250-500 ppm and spas is 200-350 ppm.
IDEAL
RANGE!