Pool Water Chemistry Questions and Answers Flashcards
6 cards from real CPO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Pool Water Chemistry Questions and Answers flashcards as text
What is the ideal pH range for a chlorinated swimming pool?
Answer: 7.2 to 7.6
The ideal pH range is 7.2 to 7.6, with 7.4 to 7.6 being optimal for chlorine effectiveness and swimmer comfort.
What is the function of total alkalinity in pool water chemistry?
Answer: To act as a pH buffer resisting rapid pH changes
Total alkalinity acts as a buffer system that resists rapid changes in pH. The ideal range is typically 80 to 120 ppm.
What causes high pH in pool water and how should it be corrected?
Answer: Aeration, high-pH chemical additions, or high alkalinity; add muriatic acid or sodium bisulfate
High pH results from aeration causing CO2 loss, use of high-pH chemicals like sodium hypochlorite, or high alkalinity. Correct with muriatic acid or sodium bisulfate.
What is the recommended calcium hardness range for a plaster pool?
Answer: 200 to 400 ppm
Calcium hardness should be maintained between 200 and 400 ppm for plaster pools to protect the surface from dissolution.
What chemical is used to raise total alkalinity without significantly affecting pH?
Answer: Sodium bicarbonate (baking soda)
Sodium bicarbonate raises total alkalinity with minimal impact on pH. Soda ash raises both pH and alkalinity significantly.
Why does rain typically cause pool pH and alkalinity to drop?
Answer: Rainwater is naturally acidic and dilutes the pool's buffering capacity
Rainwater is naturally acidic (pH approximately 5.0 to 5.5) and has zero alkalinity, so it lowers both pH and TA.