Generally, pool water needs to be replaced once every five to seven years. This should be done during mild weather so that your pool surface is not at risk from strong sunlight and heat. Your pool maintenance company can recommend when it is time to drain your pool.

Pools that are unattended, without chemicals, circulation and cleaning, don't last long. Within weeks, they become green, and within months, they become home to frogs and mosquitoes.

checking pH and chlorine levels daily. Preferably before the first swim of the day to make sure the water quality hasn't altered overnight. checking the pH and chlorine twice daily in very hot weather. monitoring chlorine levels in heated pools which need more chlorine than non-heated pools.