CPO Water Testing and Analysis Questions and Answers 2

Question 1

What is the correct procedure for collecting a pool water sample for testing?

Accepted Answer

Collect from 12 to 18 inches below the surface, away from return inlets

Answer

Samples should be taken 12 to 18 inches below the surface, away from return inlets, skimmers, and chemical feeders.

Question 2

What causes a DPD free chlorine test to show a clear result when chlorine has been added?

Accepted Answer

Chlorine bleaching from extremely high chlorine levels bleaches the DPD reagent

Answer

Very high chlorine levels above approximately 15 ppm can bleach the DPD indicator dye, giving a false zero reading.

Question 3

What is the phenol red indicator used to measure in pool water testing?

Accepted Answer

pH level

Answer

Phenol red is a pH indicator that changes color from yellow (acidic) through orange to red (basic).

Question 4

How should a pool operator verify the accuracy of their test kit?

Accepted Answer

Use a standard reference solution of known concentration

Answer

Test kit accuracy is verified using standard reference solutions with known, certified concentrations.

Question 5

What does a cyanuric acid test measure and what method is commonly used?

Accepted Answer

Stabilizer concentration using a turbidity method with melamine reagent

Answer

The CYA test uses a turbidimetric method where melamine reagent creates cloudiness proportional to CYA concentration.

CPO (Certified Pool Operator Exam) Practice Test