Pool Chemical Balance in Perth — A Practical Guide

Keeping pool water balanced is the most critical part of pool maintenance — and the part most Perth homeowners find confusing. An imbalanced pool is uncomfortable to swim in, damages equipment, and can rapidly turn green. This guide covers the essentials.

The Key Parameters

pH (ideal: 7.2–7.6): The most important measurement. Too high (alkaline) and chlorine becomes ineffective; too low (acidic) and the water irritates eyes and skin and damages equipment. Perth's tap water is slightly acidic, so pools typically need pH adjustment upward using soda ash (sodium carbonate).

Free chlorine (ideal: 1–3 ppm): The active disinfectant. Chlorine is consumed by sunlight, organic matter, and bather load. In Perth summer, pools can lose significant chlorine in a single hot day.

Total alkalinity (ideal: 80–120 ppm): Acts as a buffer for pH — helps prevent rapid pH swings. Low alkalinity makes pH harder to control.

Cyanuric acid/stabiliser (ideal: 30–50 ppm): Protects chlorine from UV degradation. Essential in Perth's sunny climate — without it, chlorine breaks down rapidly in direct sunlight.

Perth-Specific Challenges

Perth's intense summer UV destroys chlorine rapidly — stabilised chlorine (trichlor tablets or dichlor granules) helps combat this, as does running the pool pump during daylight hours. Perth water is moderately hard, which can contribute to calcium scaling on pool surfaces over time. Evaporation is also high in Perth summer — add water regularly to maintain the correct level and dilute rising calcium and TDS (total dissolved solids).

When to Call a Professional

If your pool has turned green, the chemical balance is significantly out of range, or basic adjustments aren't working, a professional pool technician can diagnose and correct the issue faster and often more cheaply than DIY trial and error.