Chlorine in Tap Water

All UK water companies have a legal obligation to disinfect our Tap Water supplies; the addition of Chlorine is the most common method. Therefore Chlorine is added at the treatment plant to combat harmful bacteria in drinking water, Chlorine levels are then also “topped up" at certain pumping stations where required. In areas of poor water quality more Chlorine is added to ensure disinfection.

The way Chlorine works is that it destroys bacteria by oxidising them, much in the same way Ozone oxidizes bacteria and small protozoa. However because of this it can also destroy beneficial bacteria such as nitosomas, which fish keepers will be aware of. At levels of 0.02mg per litre Chlorine can be harmful to certain types of fish.