LaMotte Pool & Spa Owner's Handbook - Manual (Page 8)

THE ROLE OF EACH PRIMARY
TEST FACTOR
Sanitizers - Protecting the Bather
A sanitizer must work quickly and efficiently to keep the water
environment just as healthy for 2 bathers as for 200 bathers. There are
many sanitizing systems available. The most common pool sanitizer is
chlorine and the most common spa sanitizer is bromine. Both sanitizers
are excellent oxidizers, which means they destroy or “burn out”
contaminants in the water. There are “alternative” sanitizers available
which use small amounts of chlorine or bromine to support their system
and some that
do not use chlorine or bromine at all. For the pool professionals that
recommend small amounts of chlorine or bromine be present, just
maintain a test result on the free chlorine pad with a very faint pink color.
If the pad shows a light yellow color, the result is zero and more sanitizer is
needed.
CHLORINE
When chlorine enters the water, it is in a form that is an active sanitizer
and an oxidizer called “free chlorine”. It will react with any number
of contaminants in the water. When it reacts with ammonia compounds
in the water, which come from bathers’ perspiration and urine, it becomes
“combined chlorine”. In this form, chlorine is a much slower sanitizer.
This form also causes chlorine odor and eye irritation. When using the
5-way strip, the difference between the free chlorine reading (pad 1) and
the total chlorine reading (pad 2) is the combined chlorine reading.
When the total chlorine reading is higher than the free chlorine reading,
it is time to oxidize or destroy the combined chlorine. The simplest way
is to increase the chlorine level in the pool to 10 ppm. This higher level
of chlorine will oxidize or eliminate the combined chlorine and is called
superchlorination or shock treating. Use the chlorine treatment table
found in the back of this book to determine how much chlorine should
be added based on the volume of water in your pool or spa.
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