LaMotte Pool Manager Water Quality Handbook - Manual (Page 36)

determine when a spa or hot tub should be drained. If
the TDS exceeds 1,500 ppm from the TDS at start-up, it
is a good idea to drain and refill.
Hot water systems should be kept below 104 degrees.
Small children and expectant mothers should limit their
time in hot water environments. As always, check the
local health department regulations
Pool Problems
Algae
Algae is probably the most annoying water problem in
outdoor pools since it is so unsightly and difficult to
destroy. Daily brushing and several treatments may be
required to successfully eliminate an algae problem.
Algae multiplies rapidly, so by the time the human eye
can notice it there are billions of algae cells in the pool.
The two most frequent complaints received about
public pools are related to algae and cloudy water (the
three most common colors of algae are green, black and
yellow/mustard). Green algae can make a pool especially
cloudy. Algae can clog filter systems and make pool
surfaces slippery. The best way to avoid an algae problem
is to keep at least 2.0 ppm of free available chlorine
circulating throughout the pool water at all times. For
persistent algae problems, an algicide may be used.
Nitrate and Phosphate
Nitrate and Phosphate are the two building blocks for
algae. Nitrates may enter the water from leaves or debris
but other sources of nitrates include well water supplies
and localized spraying of lawn or crop fertilizers.
Because nitrates can only be removed by draining the
water, some manufacturers have focused on removing
the other algae nutrient, phosphate. Phosphate can
occur naturally, come from fertilizers or from the
breakdown of Phosphate-based sequestering agents. A
variety of phosphate removal systems have been
introduced to eliminate the potential for algae.
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