CPO Exam Operation and Maintenance 1

Question 1

When backwashing a sand filter, the operator should stop the backwash cycle when:

Accepted Answer

The sight glass or waste discharge line runs clear

Answer

The pump motor begins to run cooler

Answer

The filter pressure gauge returns to its original clean starting pressure

Answer

30 minutes have elapsed regardless of water clarity

Question 2

After backwashing a diatomaceous earth (DE) filter, what is the required next step before returning the system to normal filtration?

Accepted Answer

Add fresh DE powder through the skimmer at the manufacturer's recommended dose

Answer

Run the pump on 'waste' mode for an additional five minutes to purge residual DE

Answer

Adjust the pH to 7.2 before restarting to protect newly exposed filter grids

Answer

Increase pump speed temporarily to compress the remaining DE on the grids

Question 3

A pool pump is running but return flow is noticeably weak, and the filter pressure gauge reads lower than normal. What is the most likely cause?

Accepted Answer

An air leak or obstruction on the suction side of the pump

Answer

The filter media is severely clogged with debris

Answer

A partially closed return valve downstream of the filter

Answer

Excessive chemical buildup on the inside of the return lines

Question 4

What is the correct procedure when changing the position of a multiport (spider) valve on a pool filter system?

Accepted Answer

Always shut the pump off completely before moving the valve handle

Answer

Slowly rotate the handle while the pump runs at low speed to avoid water hammer

Answer

Turn the valve quickly in one motion to minimize seal wear

Answer

Switch to recirculate mode first, then reposition the valve without stopping the pump

Question 5

What is the primary function of the floating weir flap located inside a pool skimmer throat?

Accepted Answer

To draw surface debris inward on a thin sheet of flow and prevent it from floating back out when the pump stops

Answer

To regulate chemical feeder flow entering the pool through the skimmer

Answer

To maintain a constant pool water level by blocking overflow

Answer

To act as a secondary strainer, capturing large debris before it reaches the pump basket

Question 6

A pool operator must achieve a 6-hour turnover rate for a 90,000-gallon commercial pool. What minimum flow rate (in GPM) is required?

Accepted Answer

250 GPM

Answer

150 GPM

Answer

200 GPM

Answer

300 GPM