We supply plenty of nutrients to feed these bacteria from our saliva, sweat, suntan lotion, cosmetics, dead skin/hair plus any urine/faecal mater
Good practice entails automatic dosing and filtration plus regular cleaning.
During use the disinfectant level should be checked every 2 hours for commercial units and twice daily for domestic hot tubs.
Monthly microbiological testing is stipulated by the HSE plus a legionella screening every 3 months.
It is believed that Jacuzzis and Hot Tubs are the source of most of the cases of Legionnaires Disease in the UK.