Any swimming needs a filtration system which gets rid of unsightly organic matter that feeds bacteria and algae plus the sanitiser that destroys any algae and bacteria that enters the water. Pumps, filters and pool cleaner in modern times remove organic matter extremely well and automatically, almost eliminating day to day maintenance. Chlorinators produce sufficient sanitiser to eliminate bacteria and algae but almost monitor the amount of sanitiser or adjust the water balance. The issue is that too much sanitiser can fade the pool colour, become corrosive, damage the pool shell and pool equipment. Also nearly all sanitisers affect water balance (pH) rendering the sanitiser useless at destroying bacteria and needing lots of corrective balancing chemicals to be added to the pool by the owner or pool specialist. A high amount of pH   causes skin irritation and red eyes.