Pool Chemistry & Water Balance
What is the ideal pH range for a properly balanced swimming pool?
- A. 6.8 to 7.0
- B. 7.2 to 7.8
- C. 7.8 to 8.2
- D. 8.0 to 8.5
Answer: B. The ideal pool pH range is 7.2 to 7.8. This range maximizes chlorine effectiveness, prevents corrosion of equipment and surfaces, and minimizes eye and skin irritation. pH below 7.2 is too acidic (corrosive); pH above 7.8 significantly reduces free chlorine efficacy.
Filtration & Circulation Systems
What is the minimum recommended turnover rate (the time for the entire pool volume to pass through the filter) for a public swimming pool?
- A. 12 hours
- B. 8 hours
- C. 6 hours
- D. 2 hours
Answer: C. Most health codes require a minimum 6-hour turnover rate for public pools, meaning the entire pool volume cycles through the filtration system at least 4 times per day. Busy pools or wading pools may require shorter turnover rates (2 to 4 hours).
Disinfection, Sanitation & Health Codes
What is the primary public health purpose of maintaining a chlorine residual in a swimming pool?
- A. To keep the water clear and blue
- B. To prevent corrosion of metal fittings
- C. To inactivate pathogens and prevent the spread of recreational water illnesses (RWIs)
- D. To maintain proper pH balance
Answer: C. The primary purpose of chlorine residual is to continuously inactivate pathogens — including bacteria (E. coli, Salmonella), viruses, and parasites (Giardia) — that are introduced by bathers. This prevents the spread of recreational water illnesses (RWIs). Clarity and pH are secondary benefits.