CERTIFIED POOL OPERATOR CPO HANDBOOK
2026 PRACTICE TEST PAPER POOL
MAINTENANCE AND SANITATION REVIEW
SHEET FULL SOLUTIONS
◉ Flow meter measurement unit. Answer: Gallons per minutes GPM
◉ what does it mean if flow meter is showing lower flow than is
should?. Answer: Usually means the filter needs to be cleaned or
there is too much debris in the strainer basket or skimmer basket
◉ 3 Types of Filters. Answer: 1. Sand Filter
2. Cartridge Filter
3. D.E. Filter
◉ Filtration. Answer: the physical process of removing suspended
particles form pool water
◉ how to clean cartridge filter. Answer: soak cartridge in degreaser
and hose off
◉ how to clean a sand filter. Answer: backwash
, ◉ Backwash. Answer: the process of reverse flow of water through
the sand filter to remove accumulated particles
◉ when to backwash. Answer: when sand filter pressure gauge is
higher than usual (spa 8-10 or higher)
◉ when can you stop backwashing. Answer: when water in sight
glass appears to be clear
◉ how often should in a sand filter be replaced. Answer: every 3-5
years
◉ Channeling. Answer: a damaging condition that occurs over time
in sand filters. When sand becomes hard, water goes around sand
and unfiltered water returns to the pool
◉ most efficient type of filter and why. Answer: D.E. filter because it
can trap particles up to 3-5 microns
◉ what happens when dirt accumulates in a filter?. Answer: the
amount of water that can pass through the filter decreases
2026 PRACTICE TEST PAPER POOL
MAINTENANCE AND SANITATION REVIEW
SHEET FULL SOLUTIONS
◉ Flow meter measurement unit. Answer: Gallons per minutes GPM
◉ what does it mean if flow meter is showing lower flow than is
should?. Answer: Usually means the filter needs to be cleaned or
there is too much debris in the strainer basket or skimmer basket
◉ 3 Types of Filters. Answer: 1. Sand Filter
2. Cartridge Filter
3. D.E. Filter
◉ Filtration. Answer: the physical process of removing suspended
particles form pool water
◉ how to clean cartridge filter. Answer: soak cartridge in degreaser
and hose off
◉ how to clean a sand filter. Answer: backwash
, ◉ Backwash. Answer: the process of reverse flow of water through
the sand filter to remove accumulated particles
◉ when to backwash. Answer: when sand filter pressure gauge is
higher than usual (spa 8-10 or higher)
◉ when can you stop backwashing. Answer: when water in sight
glass appears to be clear
◉ how often should in a sand filter be replaced. Answer: every 3-5
years
◉ Channeling. Answer: a damaging condition that occurs over time
in sand filters. When sand becomes hard, water goes around sand
and unfiltered water returns to the pool
◉ most efficient type of filter and why. Answer: D.E. filter because it
can trap particles up to 3-5 microns
◉ what happens when dirt accumulates in a filter?. Answer: the
amount of water that can pass through the filter decreases
