CPO Pool Water Chemistry Questions and Answers

Question 1

A pool operator tests the water and finds a pH of 8.0. What is the most significant consequence of this reading on the pool's sanitation?

Accepted Answer

The effectiveness of chlorine as a sanitizer will be significantly reduced.

Answer

The water will become corrosive to pool equipment.

Answer

The total alkalinity will rapidly increase, causing cloudy water.

Answer

Calcium scale will immediately begin to form on all surfaces.

Question 2

Which of the following chemical parameters acts as a 'buffer' to prevent rapid fluctuations in pH?

Accepted Answer

Total Alkalinity

Answer

Calcium Hardness

Answer

Cyanuric Acid

Answer

Total Dissolved Solids

Question 3

A pool's test results are: Total Chlorine = 3.0 ppm, Free Chlorine = 1.0 ppm. To achieve breakpoint chlorination, what is the first step a CPO should take?

Accepted Answer

Calculate the Combined Chlorine (Chloramines) level.

Answer

Add a non-chlorine shock to the pool.

Answer

Lower the pH to 7.2 before adding more chlorine.

Answer

Immediately add chlorine until the Free Chlorine reads 5.0 ppm.

Question 4

What is the primary function of Cyanuric Acid (CYA) in an outdoor swimming pool?

Accepted Answer

To protect chlorine from being destroyed by the sun's UV rays.

Answer

To lower the pH and total alkalinity.

Answer

To act as a primary sanitizer.

Answer

To prevent calcium scaling on surfaces.

Question 5

A pool operator calculates the Langelier Saturation Index (LSI) and gets a result of -0.5. What does this value indicate about the water condition?

Accepted Answer

The water is corrosive and may damage pool surfaces.

Answer

The water is perfectly balanced.

Answer

The water has a high potential for scale formation.

Answer

The water has a high level of combined chlorine.

Question 6

The ideal range for Calcium Hardness in a swimming pool is generally accepted to be:

Accepted Answer

200 - 400 ppm

Answer

50 - 100 ppm

Answer

500 - 800 ppm

Answer

Above 1000 ppm