CERTIFIED POOL OPERATOR
COMPLETE EXAM QUESTION WITH
VERIFIED ANSWERS 2026/2027
1. You operate a 120,000-gallon pool, and upon performing your hourly chemical tests
you observe the following readings: Total Available Chlorine reading is 1.6 free
available chlorine reading is 1.5 pH is 7.4 Your supervising lifeguard has just informed
you that you have had a fecal incident occur; a solid stool has been discharged into the
pool. According to the Centers for Disease Control, as the CPO, you should do the
following: - ANSWER-clear the pool and raise the free chlorine to 2 ppm
2. Assuming that your local health department requires you to raise the free chlorine to
5 ppm, how much sodium hypochlorite would be needed to raise the free chlorine in the
pool in question #1 to that level? - ANSWER-3.5 gallons
3. You are the CPO for an indoor health club pool. The facility manager informs you that
he is receiving complaints about a strong chlorine odor in the pool area, and several
members have complained of eye irritation. The most likely cause of these complaints
is: - ANSWER-high levels of chloramines in the pool
4. To determine the level of chloramines in the water, you should do which of the
following? - ANSWER-test for total chlorine and free chlorine, then subtract the free
chlorine number from the total chlorine
5. You operate a 45,000 gallon indoor pool, and upon doing your hourly chemical tests
you observe the following readings:Total available chlorine is 2.2 Free available chlorine
is 1.4 and pH is 7.6 What is the level of chloramines in this pool? - ANSWER-0.8
7. You are the operator of a 330,000 gallon outdoor pool. Your local health department
requires you to perform a water balance calculation once monthly. Upon performing the
water tests necessary to perform this calculation, you observe the following readings in
your pool: Total alkalinity is 50 ppm pH is 7.2 Calcium Hardness is 150 ppm
Temperature is 76 degrees F Total Dissolved Solids is 500 ppm Using these readings,
what is the Saturation Index for this pool? - ANSWER--0.8
8. To adjust the tested Total Alkalinity in the pool in question #7 to an acceptable level,
which chemical would be most appropriate? - ANSWER-Sodium Bicarbonate
9. To adjust the tested pH in the pool in question #7 to an acceptable level, which
chemical would be most appropriate? - ANSWER-Sodium Carbonate
10. You are the CPO for a 28,000 gallon hotel pool. You perform a water balance
chemical test, and to your surprise, the Calcium Hardness is only 100 ppm. How much
, calcium chloride (77%) would be required to increase this to 400 ppm?" - ANSWER-
100.8 lbs.
11. You are the CPO for a 100 foot long, 50 foot wide country club pool. The average
depth of this pool is 7 feet. You return to the pool on Monday morning, after a rare
weekend off, and find that the auto-fill feature has failed to work, and the pool water
level is four inches too low. How many gallons of water must be added to return the
water to the proper level? - ANSWER-12,495 gallons
12. You are the operator of a 3,000 gallon health club spa, which has an average of 100
users per day. According to the CPO Handbook, how often should the water in this spa
be changed? - ANSWER-10 days
"13. You are the CPO for a large municipal swimming pool. This pool has a volume of
560,000 gallons of water,and has an average daily bather load of 1300 people. The pool
is operated using high rate pressure sand filters. How often should you backwash the
filters?" - ANSWER-When the influent and effluent gauges are 10 to 20 psi apart
14. In testing for Chlorine/Bromine in a commercial pool, DPD is preferred over OTO
because: - ANSWER-OTO only tests for Total Chlorine
15. Safety and rescue equipment should always be: - ANSWER-Kept easily accessible
around the pool
16. Which type of filter system will remove the smallest micron particles? - ANSWER-
diatomaceous earth
17. If the pump fails to prime, which of the following does not have to be checked? -
ANSWER-filter system pressure is too high
18. Oxidation Reduction Potential testing (ORP) is measured in? - ANSWER-mV
19. High calcium hardness can result in what condition? - ANSWER-cloudy water
20. Head first entry dives are: - ANSWER-only allowed in areas of the pool that are not
marked as 'NO DIVING'
21. Opening and closing checklists: - ANSWER-all of the above
22. You can become sick from ingesting water infected with Legionella bacteria -
ANSWER-false
23. Channeling of filters occurs when: - ANSWER-the FMR is exceeded, and water cuts
a channel through the media
24. The only physical factor that affects water balance is: - ANSWER-temperature
COMPLETE EXAM QUESTION WITH
VERIFIED ANSWERS 2026/2027
1. You operate a 120,000-gallon pool, and upon performing your hourly chemical tests
you observe the following readings: Total Available Chlorine reading is 1.6 free
available chlorine reading is 1.5 pH is 7.4 Your supervising lifeguard has just informed
you that you have had a fecal incident occur; a solid stool has been discharged into the
pool. According to the Centers for Disease Control, as the CPO, you should do the
following: - ANSWER-clear the pool and raise the free chlorine to 2 ppm
2. Assuming that your local health department requires you to raise the free chlorine to
5 ppm, how much sodium hypochlorite would be needed to raise the free chlorine in the
pool in question #1 to that level? - ANSWER-3.5 gallons
3. You are the CPO for an indoor health club pool. The facility manager informs you that
he is receiving complaints about a strong chlorine odor in the pool area, and several
members have complained of eye irritation. The most likely cause of these complaints
is: - ANSWER-high levels of chloramines in the pool
4. To determine the level of chloramines in the water, you should do which of the
following? - ANSWER-test for total chlorine and free chlorine, then subtract the free
chlorine number from the total chlorine
5. You operate a 45,000 gallon indoor pool, and upon doing your hourly chemical tests
you observe the following readings:Total available chlorine is 2.2 Free available chlorine
is 1.4 and pH is 7.6 What is the level of chloramines in this pool? - ANSWER-0.8
7. You are the operator of a 330,000 gallon outdoor pool. Your local health department
requires you to perform a water balance calculation once monthly. Upon performing the
water tests necessary to perform this calculation, you observe the following readings in
your pool: Total alkalinity is 50 ppm pH is 7.2 Calcium Hardness is 150 ppm
Temperature is 76 degrees F Total Dissolved Solids is 500 ppm Using these readings,
what is the Saturation Index for this pool? - ANSWER--0.8
8. To adjust the tested Total Alkalinity in the pool in question #7 to an acceptable level,
which chemical would be most appropriate? - ANSWER-Sodium Bicarbonate
9. To adjust the tested pH in the pool in question #7 to an acceptable level, which
chemical would be most appropriate? - ANSWER-Sodium Carbonate
10. You are the CPO for a 28,000 gallon hotel pool. You perform a water balance
chemical test, and to your surprise, the Calcium Hardness is only 100 ppm. How much
, calcium chloride (77%) would be required to increase this to 400 ppm?" - ANSWER-
100.8 lbs.
11. You are the CPO for a 100 foot long, 50 foot wide country club pool. The average
depth of this pool is 7 feet. You return to the pool on Monday morning, after a rare
weekend off, and find that the auto-fill feature has failed to work, and the pool water
level is four inches too low. How many gallons of water must be added to return the
water to the proper level? - ANSWER-12,495 gallons
12. You are the operator of a 3,000 gallon health club spa, which has an average of 100
users per day. According to the CPO Handbook, how often should the water in this spa
be changed? - ANSWER-10 days
"13. You are the CPO for a large municipal swimming pool. This pool has a volume of
560,000 gallons of water,and has an average daily bather load of 1300 people. The pool
is operated using high rate pressure sand filters. How often should you backwash the
filters?" - ANSWER-When the influent and effluent gauges are 10 to 20 psi apart
14. In testing for Chlorine/Bromine in a commercial pool, DPD is preferred over OTO
because: - ANSWER-OTO only tests for Total Chlorine
15. Safety and rescue equipment should always be: - ANSWER-Kept easily accessible
around the pool
16. Which type of filter system will remove the smallest micron particles? - ANSWER-
diatomaceous earth
17. If the pump fails to prime, which of the following does not have to be checked? -
ANSWER-filter system pressure is too high
18. Oxidation Reduction Potential testing (ORP) is measured in? - ANSWER-mV
19. High calcium hardness can result in what condition? - ANSWER-cloudy water
20. Head first entry dives are: - ANSWER-only allowed in areas of the pool that are not
marked as 'NO DIVING'
21. Opening and closing checklists: - ANSWER-all of the above
22. You can become sick from ingesting water infected with Legionella bacteria -
ANSWER-false
23. Channeling of filters occurs when: - ANSWER-the FMR is exceeded, and water cuts
a channel through the media
24. The only physical factor that affects water balance is: - ANSWER-temperature
