To destroy any microorganisms introduced by patrons and other sources, a sufficient level of disinfecting chemicals must be continually present in the water, in an active form. In pools and spas using chlorine, the chemical is called free chlorine, and in facilities using bromine, the chemical is called free bromine.
Unstabilised (Indoor) Pools & Spas — Chlorine
At all times maintain a free chlorine level of at least 1.0mg/L (one milligram per litre) if the water temperature is less than 26◦C and at least 2.0mg/L if the water temperature is more than 26◦C
Stabilised (Outdoor) Pools & Spas — Chlorine
At all times maintain a free chlorine level of at least 2.0mg/L if the water temperature is less than 26◦C and at least 3.0mg/L if the water temperature is more than 26◦C
Facilities that use bromine need to maintain a level of at least 2.0mg/L where the water temperature is less than 26◦C and at least 4.0mg/L if the water temperature is more than 26◦C.
Stabiliser (Isocyanuric Acid)
Isocyanuric Acid should be maintained at a level of at least 30mg/L and no more than 60mg/L. This chemical is only required in outdoor pools and spas that use chlorine, and where they are exposed to direct sunlight.
The effectiveness of the disinfecting chemicals depends on the pH of the water. Chlorine and bromine work best when the pH reading (measure of acid or alkalinity) is between 7.2 and 7.6.
Copper Silver Ionisers
Copper-Silver Ionisers work by adding a mixture of copper and silver to the water in swimming pools and spas, and may assist by reducing the consumption of chlorine.
Domestic type ozonators produce small amounts of ozone gas, by passing a stream of air over and ultraviolet light, and injecting the gas into the pool or spa water. These systems reduce the consumption of chlorine or bromine.
It is very important that copper-silver ionisers and ozonators are used together with chlorine or bromine disinfectants, and that the concentrations of these disinfectants are maintained at normal levels.
IMPORTANT : Copper-silver ionisers and ozonators should not be used without chlorine or bromine. The levels of chlorine or bromine should not be reduced when using copper-silver ionisers or ozonators.