Arizona (Az) Cr-6 Swimming Pool Service
& Repair Contractor Examination
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. What is the ideal pH range for swimming pool water?
A. 5.0–6.0
B. 6.0–6.8
C. 7.2–7.8
D. 8.2–9.0
Correct Answer: C. 7.2–7.8
Rationale: The ideal pH range ensures swimmer comfort and effective
sanitizer performance. Chlorine works most efficiently in this range, while
water outside it can cause corrosion (low pH) or scaling and reduced
disinfection (high pH).
2. Which chemical is most commonly used as a primary sanitizer in pools?
A. Sodium bicarbonate
B. Calcium chloride
C. Chlorine
D. Copper sulfate
Correct Answer: C. Chlorine
Rationale: Chlorine is widely used because it effectively kills bacteria,
viruses, and algae while maintaining residual protection in pool water.
3. What is the purpose of a pool skimmer?
A. Heat water
, B. Remove surface debris
C. Increase chlorine levels
D. Measure pH
Correct Answer: B. Remove surface debris
Rationale: Skimmers remove floating debris such as leaves and oils before
they sink and decompose, improving water clarity and reducing filter load.
4. Total alkalinity in pool water primarily helps to:
A. Sanitize water
B. Stabilize pH
C. Increase chlorine strength
D. Remove calcium
Correct Answer: B. Stabilize pH
Rationale: Alkalinity acts as a buffer that prevents rapid pH fluctuations,
helping maintain water balance and protecting equipment surfaces.
5. What is the function of a pool pump?
A. Heat water
B. Circulate water
C. Add chemicals
D. Remove calcium hardness
Correct Answer: B. Circulate water
Rationale: The pump moves water through the filtration and treatment
system, ensuring even distribution of chemicals and proper filtration.
6. What does “free chlorine” refer to?
A. Chlorine combined with nitrogen
B. Active disinfecting chlorine
C. Chlorine locked in the filter
D. Expired chlorine
Correct Answer: B. Active disinfecting chlorine
Rationale: Free chlorine is the available form that actively sanitizes
contaminants and kills pathogens in pool water.
, 7. What is calcium hardness in pool water?
A. Amount of dissolved calcium
B. Water temperature level
C. Chlorine concentration
D. Filter pressure
Correct Answer: A. Amount of dissolved calcium
Rationale: Calcium hardness measures dissolved calcium levels, which
affect scaling or corrosion in pool surfaces and equipment.
8. Which condition is most likely caused by low calcium hardness?
A. Scaling
B. Corrosion of plaster and metal
C. Cloudy water from algae
D. High chlorine demand
Correct Answer: B. Corrosion of plaster and metal
Rationale: Low calcium hardness makes water aggressive, causing it to
leach calcium from plaster, grout, and metal components.
9. What is the main function of a pool filter?
A. Add chemicals
B. Remove suspended particles
C. Heat water
D. Increase alkalinity
Correct Answer: B. Remove suspended particles
Rationale: Filters trap dirt, debris, and fine particles, improving water
clarity and reducing contamination.
10.Which type of filter uses diatomaceous earth?
A. Sand filter
B. Cartridge filter
C. DE filter
D. Bag filter
Correct Answer: C. DE filter
& Repair Contractor Examination
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. What is the ideal pH range for swimming pool water?
A. 5.0–6.0
B. 6.0–6.8
C. 7.2–7.8
D. 8.2–9.0
Correct Answer: C. 7.2–7.8
Rationale: The ideal pH range ensures swimmer comfort and effective
sanitizer performance. Chlorine works most efficiently in this range, while
water outside it can cause corrosion (low pH) or scaling and reduced
disinfection (high pH).
2. Which chemical is most commonly used as a primary sanitizer in pools?
A. Sodium bicarbonate
B. Calcium chloride
C. Chlorine
D. Copper sulfate
Correct Answer: C. Chlorine
Rationale: Chlorine is widely used because it effectively kills bacteria,
viruses, and algae while maintaining residual protection in pool water.
3. What is the purpose of a pool skimmer?
A. Heat water
, B. Remove surface debris
C. Increase chlorine levels
D. Measure pH
Correct Answer: B. Remove surface debris
Rationale: Skimmers remove floating debris such as leaves and oils before
they sink and decompose, improving water clarity and reducing filter load.
4. Total alkalinity in pool water primarily helps to:
A. Sanitize water
B. Stabilize pH
C. Increase chlorine strength
D. Remove calcium
Correct Answer: B. Stabilize pH
Rationale: Alkalinity acts as a buffer that prevents rapid pH fluctuations,
helping maintain water balance and protecting equipment surfaces.
5. What is the function of a pool pump?
A. Heat water
B. Circulate water
C. Add chemicals
D. Remove calcium hardness
Correct Answer: B. Circulate water
Rationale: The pump moves water through the filtration and treatment
system, ensuring even distribution of chemicals and proper filtration.
6. What does “free chlorine” refer to?
A. Chlorine combined with nitrogen
B. Active disinfecting chlorine
C. Chlorine locked in the filter
D. Expired chlorine
Correct Answer: B. Active disinfecting chlorine
Rationale: Free chlorine is the available form that actively sanitizes
contaminants and kills pathogens in pool water.
, 7. What is calcium hardness in pool water?
A. Amount of dissolved calcium
B. Water temperature level
C. Chlorine concentration
D. Filter pressure
Correct Answer: A. Amount of dissolved calcium
Rationale: Calcium hardness measures dissolved calcium levels, which
affect scaling or corrosion in pool surfaces and equipment.
8. Which condition is most likely caused by low calcium hardness?
A. Scaling
B. Corrosion of plaster and metal
C. Cloudy water from algae
D. High chlorine demand
Correct Answer: B. Corrosion of plaster and metal
Rationale: Low calcium hardness makes water aggressive, causing it to
leach calcium from plaster, grout, and metal components.
9. What is the main function of a pool filter?
A. Add chemicals
B. Remove suspended particles
C. Heat water
D. Increase alkalinity
Correct Answer: B. Remove suspended particles
Rationale: Filters trap dirt, debris, and fine particles, improving water
clarity and reducing contamination.
10.Which type of filter uses diatomaceous earth?
A. Sand filter
B. Cartridge filter
C. DE filter
D. Bag filter
Correct Answer: C. DE filter
