Certified Pool Operator Handbook Practice
Test Questions with Correct Answers
2025-2026
1. You operate a 120,000
gallon pool, and upon performing your hourly chemical tests you observe the following reading
s: Total Available Chlorine reading is 1.6 free available chlorine reading is 1.5 pH is 7.4 Your sup
ervising lifeguard has just informed you that you have had a fecal incident occur; a solid stool h
as been discharged into the pool. According to the Centers for Disease Control, as the CPO, yo
u should do the following: - CORRECT 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 que
stion #1 to that level? - CORRECT ANSWER -3.5 gallons
3. You are the CPO for an indoor health club pool. The facility manager informs you that he is r
eceiving complaints about a strong chlorine odor in the pool area, and several members have c
omplained of eye irritation. The most likely cause of these complaints is: - CORRECT 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? -
CORRECT 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 obs
erve the following readings:Total available chlorine is 2.2 Free available chlorine is 1.4 and pH i
s 7.6 What is the level of chloramines in this pool? - CORRECT ANSWER -0.8
7. You are the operator of a 330,000 gallon outdoor pool. Your local health department require
s you to perform a water balance calculation once monthly. Upon performing the water tests n
ecessary to perform this calculation, you observe the following readings in your pool: Total alka
, linity is 50 ppm pH is 7.2 Calcium Hardness is 150 ppm Temperature is 76 degrees F Total Disso
lved Solids is 500 ppm Using these readings, what is the Saturation Index for this pool? -
CORRECT ANSWER --0.8
8. To adjust the tested Total Alkalinity in the pool in question #7 to an acceptable level, which c
hemical would be most appropriate? - CORRECT ANSWER -Sodium Bicarbonate
9. To adjust the tested pH in the pool in question #7 to an acceptable level, which chemical wo
uld be most appropriate? - CORRECT 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?" - CORRECT 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 fi
nd that the auto-
fill feature has failed to work, and the pool water level is four inches too low. How many gallon
s of water must be added to return the water to the proper level? - CORRECT ANSWER -
12,495 gallons
12. You are the operator of a 3,000 gallon health club spa, which has an average of 100 users p
er day. According to the CPO Handbook, how often should the water in this spa be changed? -
CORRECT 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 usi
ng high rate pressure sand filters. How often should you backwash the filters?" -
CORRECT ANSWER -When the influent and effluent gauges are 10 to 20 psi apart
Test Questions with Correct Answers
2025-2026
1. You operate a 120,000
gallon pool, and upon performing your hourly chemical tests you observe the following reading
s: Total Available Chlorine reading is 1.6 free available chlorine reading is 1.5 pH is 7.4 Your sup
ervising lifeguard has just informed you that you have had a fecal incident occur; a solid stool h
as been discharged into the pool. According to the Centers for Disease Control, as the CPO, yo
u should do the following: - CORRECT 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 que
stion #1 to that level? - CORRECT ANSWER -3.5 gallons
3. You are the CPO for an indoor health club pool. The facility manager informs you that he is r
eceiving complaints about a strong chlorine odor in the pool area, and several members have c
omplained of eye irritation. The most likely cause of these complaints is: - CORRECT 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? -
CORRECT 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 obs
erve the following readings:Total available chlorine is 2.2 Free available chlorine is 1.4 and pH i
s 7.6 What is the level of chloramines in this pool? - CORRECT ANSWER -0.8
7. You are the operator of a 330,000 gallon outdoor pool. Your local health department require
s you to perform a water balance calculation once monthly. Upon performing the water tests n
ecessary to perform this calculation, you observe the following readings in your pool: Total alka
, linity is 50 ppm pH is 7.2 Calcium Hardness is 150 ppm Temperature is 76 degrees F Total Disso
lved Solids is 500 ppm Using these readings, what is the Saturation Index for this pool? -
CORRECT ANSWER --0.8
8. To adjust the tested Total Alkalinity in the pool in question #7 to an acceptable level, which c
hemical would be most appropriate? - CORRECT ANSWER -Sodium Bicarbonate
9. To adjust the tested pH in the pool in question #7 to an acceptable level, which chemical wo
uld be most appropriate? - CORRECT 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?" - CORRECT 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 fi
nd that the auto-
fill feature has failed to work, and the pool water level is four inches too low. How many gallon
s of water must be added to return the water to the proper level? - CORRECT ANSWER -
12,495 gallons
12. You are the operator of a 3,000 gallon health club spa, which has an average of 100 users p
er day. According to the CPO Handbook, how often should the water in this spa be changed? -
CORRECT 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 usi
ng high rate pressure sand filters. How often should you backwash the filters?" -
CORRECT ANSWER -When the influent and effluent gauges are 10 to 20 psi apart
