CPO Filtration and Circulation Systems 2

Question 1

What is the primary purpose of a multiport valve on a sand filter?

Accepted Answer

To direct water flow through different filter operating modes

Answer

A multiport valve allows the operator to direct water through different flow paths for filtering, backwashing, rinsing, waste, recirculating, and closed positions.

Question 2

During a backwash cycle on a sand filter, which direction does water flow through the filter bed?

Accepted Answer

Upward through the sand

Answer

During backwash, water flows upward through the filter media, lifting and agitating the sand to flush out trapped debris.

Question 3

A cartridge filter should be cleaned when the pressure differential between inlet and outlet reaches what threshold?

Accepted Answer

10 psi above starting pressure

Answer

A cartridge filter should be cleaned when the pressure differential rises 10 psi above the clean starting pressure.

Question 4

What type of filter media is used in a diatomaceous earth (DE) filter?

Accepted Answer

Fossilized diatom skeletons coated on grids

Answer

DE filters use grids or fingers coated with diatomaceous earth — the fossilized remains of microscopic algae — as their filter media.

Question 5

What is 'channeling' in a sand filter?

Accepted Answer

A condition where water bypasses the media through cracks or channels

Answer

Channeling occurs when water finds preferential pathways through cracks or voids in the filter media, bypassing proper filtration.

CPO (Certified Pool Operator Exam) Practice Test

CPO (Certified Pool Operator Exam) Practice Test

CPO Filtration and Circulation Systems 2