CAT Aquatic Technicians Skills and Knowledge Areas 5

Question 1

A pool owner reports that the water is cloudy only in the morning but clears up by afternoon. What is the most likely cause?

Accepted Answer

pH rising overnight due to CO2 off-gassing, causing calcium to precipitate

Answer

Algae blooming overnight in the absence of UV light

Answer

Insufficient filtration run time — the pump runs only during the day

Answer

Bather load is highest in the morning hours

Question 2

What chemical is used to raise a pool's total alkalinity without significantly affecting pH?

Accepted Answer

Sodium bicarbonate (baking soda)

Answer

Sodium carbonate (soda ash)

Answer

Sodium bisulfate (dry acid)

Answer

Calcium chloride

Question 3

A technician is calculating pool volume to dose chemicals. The pool is rectangular: 30 ft long, 15 ft wide, and averages 5 ft deep. What is the approximate volume in gallons?

Accepted Answer

16,875 gallons

Answer

14,850 gallons

Answer

22,500 gallons

Answer

33,750 gallons

Question 4

Which of the following best describes 'cavitation' in a pool pump?

Accepted Answer

Air bubbles forming and collapsing inside the pump due to insufficient water supply, causing damage

Answer

The pump running in reverse due to a wiring error

Answer

Excessive backpressure causing the impeller to stall

Answer

Calcium deposits forming inside the pump volute

Question 5

For a commercial aquatic facility, what is the minimum required turnover rate for a pool according to most state health codes?

Accepted Answer

Once every 6 hours

Answer

Once every 12 hours

Answer

Once every 8 hours

Answer

Once every 4 hours

Question 6

A pool test shows pH of 7.8 and total alkalinity of 120 ppm. To lower pH without significantly affecting alkalinity, the technician should use:

Accepted Answer

Sodium bisulfate (dry acid) or muriatic acid added slowly near a return jet

Answer

Sodium carbonate added at the deep end

Answer

Trichlor pucks added to the skimmer

Answer

CO2 injection system set to maximum output overnight

Question 7

What is the purpose of a 'dead man' or emergency shutoff switch required near commercial pools?

Accepted Answer

To immediately stop all pump and circulation equipment in an emergency to aid rescue operations

Answer

To automatically dose emergency levels of chlorine during a fecal incident

Answer

To lock the pool gate and activate underwater lighting during a rescue

Answer

To alert the local fire department when a drowning is detected