CAT Aquatic Technicians Skills and Knowledge Areas 2

Question 1

A pool's total alkalinity reads 60 ppm. What is the most likely consequence if left uncorrected?

Accepted Answer

pH will fluctuate widely and be difficult to control

Answer

pH will become highly stable and resistant to change

Answer

Chlorine demand will decrease significantly

Answer

Calcium hardness will automatically increase

Question 2

Which type of filter media requires backwashing to clean and uses the finest filtration of the three common types?

Accepted Answer

Diatomaceous Earth (DE)

Answer

Sand

Answer

Cartridge

Answer

Zeolite

Question 3

When shocking a pool with calcium hypochlorite, a technician should always:

Accepted Answer

Pre-dissolve the shock in a bucket of pool water before adding

Answer

Add the shock directly to the skimmer basket

Answer

Add shock while the pump is off to allow it to settle

Answer

Mix shock with muriatic acid first to boost effectiveness

Question 4

A residential pool pump is running but flow rate has dropped significantly. The filter pressure gauge reads normal. What is the most likely cause?

Accepted Answer

Worn pump impeller or clogged pump strainer basket

Answer

Filter media needs replacement

Answer

Heater bypass valve is open

Answer

Cyanuric acid levels are too high

Question 5

What is the recommended free chlorine level (in ppm) for a residential swimming pool according to standard industry guidelines?

Accepted Answer

1.0–3.0 ppm

Answer

0.5–1.0 ppm

Answer

3.5–5.0 ppm

Answer

5.0–8.0 ppm

Question 6

Cyanuric acid (CYA) is used in outdoor pools primarily to:

Accepted Answer

Stabilize chlorine against UV degradation from sunlight

Answer

Increase total alkalinity without affecting pH

Answer

Prevent calcium scaling on pool surfaces

Answer

Enhance the effectiveness of algaecides

Question 7

A pool technician notices a strong chlorine odor and swimmer eye irritation despite a free chlorine reading of 3.0 ppm. What is the most likely cause?

Accepted Answer

High concentration of chloramines (combined chlorine)

Answer

Free chlorine is too high

Answer

pH is above 8.0

Answer

Calcium hardness is too low