CAT Aquatic Technicians Skills and Knowledge Areas 3

Question 1

Which method is used to eliminate chloramines from a pool by adding enough chlorine to reach a specific oxidation threshold?

Accepted Answer

Breakpoint chlorination (typically 10x the combined chlorine level)

Answer

Breakpoint chlorination requires adding chlorine to approximately 10 times the combined chlorine reading to fully oxidize chloramines.

Question 2

A pool heater fails to ignite. After confirming gas supply is adequate, what should the technician check next?

Accepted Answer

Flow switch or pressure switch to ensure adequate water flow

Answer

Pool heaters have a flow switch or pressure switch that prevents ignition if water flow is insufficient, protecting the heat exchanger.

Question 3

When reading a multiport valve position, 'RECIRCULATE' bypasses which component?

Accepted Answer

The filter

Answer

The RECIRCULATE position sends water from the pump back to the pool without passing through the filter media.

Question 4

What does a saturation index (Langelier Saturation Index) value of +0.5 indicate about pool water?

Accepted Answer

The water is slightly scale-forming

Answer

An LSI above 0 indicates scale-forming (calcium deposits) tendency; +0.5 is mildly scale-forming but outside the ideal -0.3 to +0.3 range.

Question 5

A salt chlorine generator (SWG) is producing low chlorine output even though salt levels are correct. What is the most common cause?

Accepted Answer

Calcium buildup on the electrolytic cell plates

Answer

Calcium scale deposits on the electrolytic cell reduce its ability to generate chlorine and must be cleaned with an acid wash.

(CAT) Certified Aquatic Technicians Practice Test