Pool & Spa Maintenance & Operations Flashcards

What does 'combined chlorine' represent in pool water chemistry?

Answer: Chlorine that has reacted with ammonia and nitrogen compounds

Combined chlorine (chloramines) forms when free chlorine reacts with ammonia and nitrogen compounds from bathers, and it is much less effective as a sanitizer.

Which condition would most likely cause a pool to have a low Langelier Saturation Index (LSI)?

Answer: Low pH, low alkalinity, and low calcium hardness

A negative LSI (corrosive water) results from low pH, low total alkalinity, and low calcium hardness, which causes water to be aggressive and corrode surfaces and equipment.

At what cyanuric acid (stabilizer) level should a pool operator take corrective action by diluting the pool water?

Answer: Above 100 ppm

Most health codes require corrective action (partial drain and refill) when cyanuric acid exceeds 100 ppm, as higher levels significantly reduce chlorine effectiveness.

A spa operator wants to heat water to the maximum allowable temperature. What is the standard maximum for public spas?

Answer: 104°F (40°C)

The maximum recommended and most commonly regulated temperature for public spas is 104°F (40°C) to prevent hyperthermia.

What is the purpose of 'shocking' or 'superchlorinating' a pool?

Answer: To eliminate combined chlorine and kill resistant organisms

Superchlorination raises free chlorine to 10x the combined chlorine level to oxidize chloramines and destroy algae, bacteria, and other contaminants.

Which measurement indicates the water's ability to resist changes in pH?

Answer: Total alkalinity

Total alkalinity acts as a pH buffer, resisting rapid changes in pH and keeping it stable within the desired range.

In a recirculation system, what is the correct order of water flow from the pool to return?

Answer: Pump → filter → heater → chemical feeders → pool

Water flows from the pool through the pump (which creates suction and pressure), then through the filter for cleaning, then through the heater, and finally past chemical feeders before returning to the pool.