Chlorine dioxide liquid is a safe and effective method of disinfecting water they kill bacteria viruses and cysts in water including giardia and crytosporidium they have a quick reaction time and leave much less residual taste than ordinary chlorine treats up to 60 litres of water once water has been purified it should be kept in a sealed container the container should be either kept in a dark area where no light is allowed when using any water treatment product the water should