Pools 2017 Flashcards
How should samples be taken from a swimming pool?
samples should be taken at 12-18” depth with forward sweeping motion
What does Orthotoluene do?
measures total residual chlorine
this test is heat sensitive
What is DPD and what does it do?
diethyl-phenylene-diamine
measures free and combined levels of chlorine
not heat sensitive
more accurate than Ortho tests
What are recirculating swimming pools and the minimum turnover?
traditional pools
pools - 6 hours
spas - 0.5 hrs
wading pools - 1 hr
What is the ideal pH of a pool?
7.2-7.8
What happens when a pool pH is too low? Too high?
pH<7 - corrosion
pH>7 - scale deposits
What is sodium thiosulfate and when is it used in pools?
chemical that neutralizes chlorine
used when free Cl may affect test results
What are soda ash and caustic soda alternatively know as and what are their purposes?
soda ash - sodium carbonate
caustic soda - sodium hydroxide
bases used to raise pool pH
What is muriatic acid alternatively known as and what is it used for?
hydrochloric acid
used to lower pH
What is Cyanuric acid and when should it be used?
chlorine stabilizer which prevents excessive dissipation of Cl from sun light exposure
should be used when levels between 40-60ppm (Cl maintained at 1.5 ppm min)
Ineffective if >100 ppm
What is significant about copper in pools?
if Cu test performed and resulting concentrations of >0.2 ppm, pool water needs to be changed
When should clarity be an important consideration in pool inspections?
pool to be closed if bottom pool main drain is not visible due to cloudiness
What is copper sulfate used for in pools?
to control algae growth problems
How do you calculate the occupancy load of a pool?
surface area of pool/20
How do you calculate the occupancy load of a spa?
surface area of spa/10
