Water Chemistry is 1 of 5 key factors of maintaining a pool's health.

Other factors are;

Pure Water has a neutral pH of 7 - which is neither acidic (<7) nor alkaline (>7)

Crucial for sanitation chemicals to work effectively

Prolongs the life of the pool surfaces and equipment

Essential for bather comfort

Balanced water is clean water

Alkalinity - also know as buffer. Measure of water's ability to resist change in pH

                   Ideal range - 80-120 ppm

If too low - green water, etching and staining of pool surface, corrosion of metal parts, rapid fluctuation of pH

If too high - cloudy water, reduced chlorine efficiency, pH will keep increasing regardless of acid added, 

pH - measure of hydrogen ion activity.

        Ideal range - 7.2 - 7.4

If too low - erosion of pool infrastructure and equipment, rapid dissipation of chlorine

If too high - scale formation, cloudy water, reduced chlorine efficiency

Calcium Hardness - referred to as hard or soft water, used as a sacrificial mineral to keep pool water from leaching other minerals

                                  Ideal range -100-300 ppm

If too low - corrosion of pool infrastructure and equipment

If too high - chalk deposits/scale on pool infrastructure

Sanitises the water

Kills viruses, bacteria and protozoa

Chlorine - measured as free and combined, used by 90% of pools,  UV light halves the levels every 35 mins

                  Ideal range - 1-3 ppm

If too low - pathogens in the water

If too high - bather discomfort

Bromine - ideal for INDOOR pools and spas, 

                  Ideal range - 2-4 ppm

Combats algae

Clears cloudy water

Provides UV protection

Removes algae food source

Removes metals

Phosphates - added to water from bathers, organic debris, lawn care products, food source for algae, can be removed with phosphate remover

                       Ideal range - 0-0.1 ppb

If too low - no dramas

If too high - potential for algae bloom

Copper & Iron - added to water by copper based algaecides, corroded equipment, plumbing infrastructure, can cause staining, can be removed with metal                                     remover

                           Ideal range - 0-0.3 ppm

If too low - no dramas

If too high - pool staining

UV Blockout - aka sunblock, component of stabilised chlorine, known technically as cyanuric acid, protects chlorine from UV effects

                         Ideal range - 30-100 ppm

If too low - free chlorine dissipates quickly in sunlight

If too high - reduced chlorine efficiency, cloudy/milky pool water

Clarifiers - known as flocculent, keeps the water clear, removes phosphates, adds extra sparkle, prevents oil scum marks, improves filtration