66
of pool water may be changed to a beautiful blue by over-chlorination. This
treatment gives rise to the formation of a rusty precipitate which settles to
the bottom of the pool. This sediment may be iron or iron organisms. Possibly
this lessening of turbidity may lead to greater reflection of the blue part of
the spectrum. Use of the elgaecide, copper sulphate, may also have an effect
on the color of the water. The presence of chemicals, color, or organic
matter in pools may add both to their cloudiness and to their cost of operation
by increasing their chlorine demand,

In certain pools where both ammonia and chlorine are used, excessive
amounts of nitrites may occur and interfere vith the accuracy of the ortho-
tolidine test for residual chlorine, Nitrites may be found in pools where
chloramine is not used. Frequent determination for nitrites should be made,
and the ortho-tolidine solution used should be such as not to be influenced by
them,

The amount of available or excessive chlorine in a pool should not be
less than 0.4 p.p.m, nor more than 0;6 p.D.»ms This can best be obtained by.
the use of chlorine as a gas or in water solution and by continuous rather than
by intermittent dosage. Eigh alkalinity of the water is said to have a definite
effect in the reduction of the loss of chlorine from disinfected swimming pools
and to cause less trouble with chlorine odors,

Chloramines are slover acting disinfectents then chlorine end to this
extent are not so safe, They are, hovever, more lasting and higher disinfectant
dosages mav be carricd without causing irritation of the eyes end nose, In
large or outdoor pools, chloramine may also have certain advantages. “here it
is used, the amount available should not be less than 0,7 p.p.m. nor more than
1.0 psp.em.

Bathing Beach Biology

The most troublesome organism to be found at bathing beaches is a
species of anthropoid often called Homo Sapiens, or "Man, the Wise," This
designation is a misnomer because this form of life is often neither vise nor
manly. These vertebrates will sometimes multinly so rapidly in a pool that
those on the svimming board ~ill be jumping on those in the ~eter, crippling
or drowning them. The more adventuresome “ill climb into tovrers, balconies,
rafters, or trees and dive head first into shallo~ vater, killing themselves and
interferring vith the operation of the pool,

At bathing becehes "Homo, the San" fills himself “ith sizzling stcaks
or fried chicken and immediately plunges into the lake to demonstrate how far
he can svrim in deep water on a full stomach before he dromns, Year after year
this experiment creates great excitement at summer resorts, causes lifeguards
endless headaches, gives fishermen a chance to make a fer dollars vith their
grappling irons, end stimletes the underte’-ing industry.

As a rule most warm-blooded animals ~ill avoid cold water end will not
deliberately go beyond their depth, ven polar bears ill not brea through
ice in winter to stend shivering in ice water “hile photographs are made for
the rotograyvure section of the police gazette,

Warnings mean little to Fomo. He ~ill plunge into deen fresh water
lakes in early summer, stiffen, cramp and go dorm, He will defy currents and
tides to be dromned. He often seems possessed vith the fixed idea that if he
can not swim in water up to his neck, he will do so with ease ~here it is forty
feet deep, This naranoia has ruined many vacations and has cost insurance