Practice Test GeeksCPO (Certified Pool Operator Exam) Practice Test
← All CPO Flashcard Decks

Water Testing and Analysis Flashcards

7 cards from real CPO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Water Testing and Analysis flashcards as text

  1. How is the combined chlorine (chloramine) level calculated from pool water test results?

    Answer: Total chlorine minus free chlorine

    Combined chlorine equals total chlorine minus free chlorine; it represents chlorine that has reacted with nitrogen compounds and lost its disinfecting power.

  2. What is the primary function of cyanuric acid (CYA) when added to outdoor swimming pool water?

    Answer: Protects free chlorine from degradation by UV sunlight

    Cyanuric acid bonds with hypochlorous acid and shields it from UV radiation, significantly extending the effective lifespan of chlorine in outdoor pools.

  3. ORP (Oxidation-Reduction Potential), used to assess pool water disinfection efficacy, is measured in which unit?

    Answer: Millivolts (mV)

    ORP is an electrochemical measurement expressed in millivolts that indicates the overall oxidizing power and disinfection capacity of the water.

  4. An ORP reading of 650–750 mV in a properly maintained pool typically indicates which condition?

    Answer: Adequate disinfection with effective pathogen control

    Most health authorities consider an ORP of 650–750 mV the range that provides effective pathogen inactivation in pool water.

  5. When the combined chlorine (chloramine) level exceeds 0.2 ppm, what is the recommended corrective action?

    Answer: Perform breakpoint chlorination (superchlorination)

    Breakpoint chlorination involves adding enough chlorine to oxidize and destroy chloramines, restoring effective free chlorine levels.

  6. A phenol red test kit is the standard colorimetric tool used to measure which water parameter?

    Answer: pH level

    Phenol red is a pH indicator dye that produces colors ranging from yellow (pH ~6.8) to red/violet (pH ~8.4) for visual comparison against a chart.

  7. Which chemical form of chlorine is responsible for causing eye and skin irritation and the characteristic 'pool smell'?

    Answer: Combined chlorine (chloramines)

    Chloramines (combined chlorine) are the irritating byproducts formed when free chlorine reacts with ammonia and nitrogen compounds introduced by bathers.