POOL OPERATOR 2026 TEST PAPER QUESTIONS AND
ANSWERS RATED A+
✔✔combined chlorine - ✔✔forms when free chlorine reacts with 2 types of
contaminants in the water
✔✔pathogens - ✔✔bacteria, fungi, viruses and protozoan parasites
✔✔available chlorine content (acc) - ✔✔-comparison of the relative amount of chlorine
released into water for different chlorine disinfectants
-developed using chlorine gas as the standard reference of 100%
✔✔active chlorine percentage - ✔✔the percentage by weight of the technical grade
active ingredient in the product
✔✔how does sodium hypochlorite raise the water's Total Dissolved Solids? - ✔✔by
adding sodium (Na+) and chloride (Cl-) ions to the water
✔✔sodium hypochlorite (NaOCl) - ✔✔-liquid chlorine releasing disinfectant that is the
most common disinfectant used
-active strength: 10-12%
-ACC 10-12%
-pH 9-14
✔✔calcium hypochlorite is used to - ✔✔superchlorinate the water
✔✔calcium hypochlorite - ✔✔-dry form of chlorine
-class 3 oxidizer
-continuous use may result in high calcium levels
-pH 8.5-11
✔✔lithium hypochlorite (LiOCl) - ✔✔-dry, granular compound of chlorine
-rapidly and completely soluble
-use for superchlorination
-class 1 oxidezer
✔✔chlorine generation - ✔✔in line generation
brine method
✔✔chlorine gas - ✔✔-effective disinfectant
-active strength 100%
-ACC 100%
-pH 0
, ✔✔cyanuric acid (CyA) - ✔✔-aka conditioner/stabilizer
-added directly or indirectly via stabilized chlorine products
-protect chlorine from UV light and sunlight
-stabilizes FC but not bromine
-maintain between 30 and 50 ppm
✔✔excessive levels of CyA may lead to - ✔✔an increased risk of algae
✔✔the most common method of reducing CyA concentration is - ✔✔to partially drain
and replace water with fresh potable water
✔✔unstabilized disinfectants are - ✔✔sodium hypochlorite
calcium hypochlorite
lithium hypochlorite
chlorine gas
✔✔unstabilized disinfectants - ✔✔-aka inorganic disinfectants
-sensitive to UV radiation and sunlight
-easily automated and controlled by an oxidation reduction potential
✔✔stabilized disinfectants - ✔✔-contain cyanuric acid as part of their molecular
structure
✔✔trichlor - ✔✔-dry compound
-class 1 oxidizer
-low solubility
-lowers the total alkalinity and pH over time
-stabilizes
-releases cyanuric acid into the water
✔✔dichlor - ✔✔-anhydrous
-dichlor dihydrate
-a salt, very soluble
-used to superchlorinate pool and raise stabilizer level
✔✔anhydrous dichlor - ✔✔-no water is bound to molecule
-class 3 oxidizer
✔✔dichlor dihydrate - ✔✔class 1 oxidizer
✔✔bromine - ✔✔-disinfectant
-oxidizer
-reddish brown liquid
✔✔hypobromous acid (HOBr) - ✔✔-weak acid
ANSWERS RATED A+
✔✔combined chlorine - ✔✔forms when free chlorine reacts with 2 types of
contaminants in the water
✔✔pathogens - ✔✔bacteria, fungi, viruses and protozoan parasites
✔✔available chlorine content (acc) - ✔✔-comparison of the relative amount of chlorine
released into water for different chlorine disinfectants
-developed using chlorine gas as the standard reference of 100%
✔✔active chlorine percentage - ✔✔the percentage by weight of the technical grade
active ingredient in the product
✔✔how does sodium hypochlorite raise the water's Total Dissolved Solids? - ✔✔by
adding sodium (Na+) and chloride (Cl-) ions to the water
✔✔sodium hypochlorite (NaOCl) - ✔✔-liquid chlorine releasing disinfectant that is the
most common disinfectant used
-active strength: 10-12%
-ACC 10-12%
-pH 9-14
✔✔calcium hypochlorite is used to - ✔✔superchlorinate the water
✔✔calcium hypochlorite - ✔✔-dry form of chlorine
-class 3 oxidizer
-continuous use may result in high calcium levels
-pH 8.5-11
✔✔lithium hypochlorite (LiOCl) - ✔✔-dry, granular compound of chlorine
-rapidly and completely soluble
-use for superchlorination
-class 1 oxidezer
✔✔chlorine generation - ✔✔in line generation
brine method
✔✔chlorine gas - ✔✔-effective disinfectant
-active strength 100%
-ACC 100%
-pH 0
, ✔✔cyanuric acid (CyA) - ✔✔-aka conditioner/stabilizer
-added directly or indirectly via stabilized chlorine products
-protect chlorine from UV light and sunlight
-stabilizes FC but not bromine
-maintain between 30 and 50 ppm
✔✔excessive levels of CyA may lead to - ✔✔an increased risk of algae
✔✔the most common method of reducing CyA concentration is - ✔✔to partially drain
and replace water with fresh potable water
✔✔unstabilized disinfectants are - ✔✔sodium hypochlorite
calcium hypochlorite
lithium hypochlorite
chlorine gas
✔✔unstabilized disinfectants - ✔✔-aka inorganic disinfectants
-sensitive to UV radiation and sunlight
-easily automated and controlled by an oxidation reduction potential
✔✔stabilized disinfectants - ✔✔-contain cyanuric acid as part of their molecular
structure
✔✔trichlor - ✔✔-dry compound
-class 1 oxidizer
-low solubility
-lowers the total alkalinity and pH over time
-stabilizes
-releases cyanuric acid into the water
✔✔dichlor - ✔✔-anhydrous
-dichlor dihydrate
-a salt, very soluble
-used to superchlorinate pool and raise stabilizer level
✔✔anhydrous dichlor - ✔✔-no water is bound to molecule
-class 3 oxidizer
✔✔dichlor dihydrate - ✔✔class 1 oxidizer
✔✔bromine - ✔✔-disinfectant
-oxidizer
-reddish brown liquid
✔✔hypobromous acid (HOBr) - ✔✔-weak acid
