CPO Filtration & Circulation Systems Flashcards

What is the standard turnover rate required for most public swimming pools?

Answer: 6 hours

Most public pools require a 6-hour turnover rate, meaning the entire pool volume must pass through the filtration system at least once every 6 hours.

When should a sand filter be backwashed?

Answer: When pressure rises 8–10 psi above the clean operating pressure

A sand filter should be backwashed when the pressure gauge reads 8–10 psi above the initial clean/starting pressure, indicating accumulated debris.

What is the primary purpose of a hair and lint strainer (pump strainer basket)?

Answer: To protect the pump impeller from debris damage

The hair and lint strainer captures large debris before it reaches and damages the pump impeller, protecting the pump from wear and clogging.

What filtering medium is used in a diatomaceous earth (DE) filter?

Answer: Fossilized algae powder coated onto filter grids

DE filters use diatomaceous earth — a powder made from fossilized microscopic algae — coated on filter grids to achieve very fine particle filtration.

What causes 'channeling' in a sand filter?

Answer: Water finding preferential paths through worn sand instead of flowing evenly

Channeling occurs when water bypasses proper filtration by carving paths through degraded or compacted sand, significantly reducing filter effectiveness.

What is the main water conservation advantage of a cartridge filter over a sand filter?

Answer: It does not require backwashing, saving significant water during maintenance

Cartridge filters are cleaned by rinsing with a hose rather than backwashing, eliminating the large volumes of water wasted during sand filter backwash cycles.