Pool Chemical Tips: Understanding the effects of stabiliser

Most pool owners in Australia add stabiliser – cyanuric acid, also known as CYA – to their pools in order to prevent the chlorine being dissipated by UV (sunlight).

Recommended levels of stabiliser in Australia are 20ppm to 50ppm with many retailers recommending towards the higher level.

What is often not understood is that 30ppm of CYA will provide about 96 per cent effective protection against UV.

However 50ppm offers about 98 per cent protection – but the bacteria kill time almost doubles and the ORP level will drop significantly.

Cyanuric acid levels

If possible, CYA levels should be maintained at about 25ppm to 30ppm which will give an ideal balance of UV protection and chlorine effectiveness. This assumes of course that pH levels are maintained at 7.2 to 7.4 because as we all know, a pH above 7.4 significantly affects the level of HOCL (active chlorine).

We do know that, don’t we??

These tips are supplied by pool industry pioneer and chemistry expert David Lloyd. For more information on this or any other technical enquiries call International Quadratics on (02) 9774 5550.