Filtration and Circulation Systems Flashcards
7 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 7 Filtration and Circulation Systems flashcards as text
What is the recommended flow rate range for sand filters used in commercial pools?
Answer: 3–5 gallons per minute per square foot
Sand filters for commercial pools operate at a flow rate of 3–5 gallons per minute per square foot of filter surface area.
After backwashing a sand filter, what position should the multiport valve be set to before returning to filter mode?
Answer: Rinse
After backwashing, the valve should be set to the Rinse position for about 30–60 seconds to reseat the sand and clear any debris from the laterals before returning to Filter.
The turnover rate for a wading pool or kiddie pool is typically:
Answer: Every 2 hours or less
Wading or kiddie pools require a faster turnover — typically every 1–2 hours — due to higher bather load relative to volume and greater contamination risk.
Which of the following best describes the function of the skimmer weir?
Answer: It regulates the flow of surface water into the skimmer
The skimmer weir is a floating flap that regulates the flow of surface water into the skimmer, maximizing removal of oils and debris from the water surface.
What is cavitation in a pool pump?
Answer: Formation and collapse of vapor bubbles due to low suction pressure
Cavitation occurs when low suction pressure causes water to vaporize, forming bubbles that collapse violently and damage the pump impeller.
What does 'filter aid' refer to in the context of DE filtration?
Answer: Fresh DE powder added after backwashing to recoat the grids
Filter aid is fresh diatomaceous earth added through the skimmer after backwashing to recoat the filter grids and restore filtration efficiency.
The pressure gauge on a filter system reads 28 psi and the normal operating pressure is 15 psi. What is the most likely cause?
Answer: The filter media is clogged and needs cleaning or backwashing
A pressure reading significantly higher than the baseline (28 vs. 15 psi) indicates the filter media is clogged, restricting flow and building pressure.