Practice Test Geeks(CPI) Certified Pool & Spa Inspector Practice Test
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Water Quality & Treatment Standards Flashcards

7 cards from real CPI 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 Quality & Treatment Standards flashcards as text

  1. What is the maximum recommended bromine level for a residential spa?

    Answer: 3–5 ppm

    For residential spas using bromine, the recommended range is 3–5 ppm, providing effective disinfection at elevated spa temperatures.

  2. Why is cyanuric acid (CYA) NOT recommended for use in indoor pools?

    Answer: Indoor pools have no UV exposure, so CYA provides no benefit while raising TDS

    CYA stabilizes chlorine against UV degradation from sunlight; indoor pools have no UV exposure, making CYA unnecessary and just a TDS contributor.

  3. During a pool inspection, the inspector finds the ORP (oxidation-reduction potential) reading at 650 mV. What does this indicate?

    Answer: The water has adequate disinfection capacity for safe swimming

    An ORP reading of 650–750 mV is generally considered acceptable, indicating sufficient oxidizing capacity for effective disinfection.

  4. What effect does a high cyanuric acid level (above 100 ppm) have on chlorine's ability to kill pathogens?

    Answer: Chlorine's effective kill rate slows dramatically (chlorine lock)

    Excessive CYA binds chlorine molecules, dramatically reducing the concentration of free hypochlorous acid available for disinfection — a condition called 'chlorine lock.'

  5. Which chemical is used to RAISE total alkalinity in pool water?

    Answer: Sodium bicarbonate (baking soda)

    Sodium bicarbonate is the standard product used to raise total alkalinity without significantly affecting pH.

  6. A pool inspector finds heavy calcium scale deposits on the tile line and equipment. The Langelier Saturation Index (LSI) is +0.8. What corrective action is indicated?

    Answer: Lower pH, reduce calcium hardness, and/or reduce alkalinity to bring LSI toward zero

    A high positive LSI indicates scale-forming water; the fix is reducing one or more of pH, calcium hardness, or alkalinity to bring LSI closer to 0.

  7. What is the primary purpose of shocking (superchlorinating) a pool after a heavy rainstorm?

    Answer: To oxidize contaminants and nitrogen compounds washed in and restore chlorine residual

    Rainwater introduces organic matter, nitrogen compounds, and contaminants that increase chlorine demand; shocking oxidizes these contaminants and restores adequate sanitizer levels.