CPI Cheat Sheet 2026

The 30 highest-yield CPI facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the primary risk of storing liquid chlorine (sodium hypochlorite) near dry acid (sodium bisulfate) in a pool chemical storage room? → Release of toxic chlorine gas
2. Which condition found during inspection would indicate a pool pump impeller is partially clogged? → Pump motor runs but flow rate is significantly lower than expected
3. Which of the following is a fundamental principle of sand, de & cartridge filtration as it applies to Certified Pool & Spa Inspector? → Systematic evaluation and adherence to established industry standards
4. For a gas pool heater, what is the purpose of the pilot assembly or ignition control module? → To ignite the main burner and verify the flame is established
5. A pool deck using pavers over a sand base has multiple sunken areas near the pool edge. The inspector's FIRST concern should be: → Whether pool water is leaking and undermining the sand base
6. When photographing a pool during an inspection, which image is most critical to include in the report? → A photo of every deficiency identified, showing the specific location and condition
7. A pool inspection report should categorize a missing GFCI protection for a 120V receptacle within 20 feet of the pool as: → A safety hazard requiring immediate correction
8. An inspector finds a DE filter with no pressure gauge installed. This is a concern because: → Without a gauge, operators cannot determine when the filter needs servicing
9. Per NEC 680.26, the equipotential bonding grid must include all metal within the pool structure and all metal within how many inches of the pool water? → 5 feet (60 inches)
10. How often should cartridge filter elements typically be replaced under normal residential pool use? → Every 1–2 years
11. Why should pool water be tested regularly? → To prevent algae and ensure chemical balance
12. Which federal law mandates that all public pool and spa drain covers meet specific anti-entrapment standards? → Virginia Graeme Baker Pool and Spa Safety Act (VGB Act)
13. A spa or hot tub with a lockable safety cover that meets ASTM F1346 standards may be exempt from which barrier requirement? → The surrounding barrier fence requirement
14. A CPI professional encounters an unfamiliar situation while performing electrical bonding & gfci requirements duties. What is the most appropriate first action? → Consult relevant standards, guidelines, or a qualified supervisor before proceeding
15. A CPI inspector notices that a pool's recirculation pump has no GFCI protection and is located within 5 feet of the pool. What code is violated? → NEC Article 680 requiring GFCI protection for pool-associated electrical equipment
16. Which chemical should NEVER be used to clean a DE filter grid or cartridge filter element because it destroys the filter media? → Muriatic acid
17. Under most state health codes, what is the minimum required turnover rate for a public swimming pool? → Every 6 hours
18. Which chemical is used to LOWER pool water pH? → Muriatic acid (hydrochloric acid)
19. What minimum clearance is typically required around a gas pool heater for proper combustion air and serviceability? → Clearances specified on the heater's nameplate and local codes must be maintained
20. An inspector observes rust staining along the waterline of a concrete pool shell. What structural concern does this MOST strongly suggest? → Corrosion of embedded reinforcing steel
21. A gunite pool has a return line that passes through the bond beam without a sleeve. What is the inspector's concern? → Differential movement between the pipe and concrete can crack the pipe or bond beam
22. What does 'variance' mean in the context of state pool health codes? → An official exemption from a specific code requirement granted by the authority
23. Which structural deficiency is a CPI inspector MOST likely to find in an older gunite pool built without adequate steel reinforcement? → Widespread cracking due to insufficient tensile strength
24. Which of the following best describes the Langelier Saturation Index (LSI) as used in commercial pool operation? → A scale indicating whether water is corrosive, balanced, or scale-forming
25. Which of the following is a fundamental principle of commercial pool operator standards as it applies to Certified Pool & Spa Inspector? → Systematic evaluation and adherence to established industry standards
26. Total dissolved solids (TDS) in pool water above 2,000 ppm above the source water level typically causes which issue? → Reduced effectiveness of pool chemicals and potential corrosion
27. Under NEC 680.22(A), GFCI protection is required for all 120V receptacles located within how many feet of the inside wall of a swimming pool? → 20 feet
28. What minimum free chlorine concentration is generally required to achieve breakpoint chlorination and destroy chloramines? → 10 times the combined chlorine level
29. Under state health codes, what is typically required when a public pool's free chlorine residual drops below the minimum acceptable level? → Close the pool until levels are restored
30. A CPI professional encounters an unfamiliar situation while performing pump, motor & heater inspection duties. What is the most appropriate first action? → Consult relevant standards, guidelines, or a qualified supervisor before proceeding