Home brewers use reducing agents such as sodium metabisulfite or potassium metabisulfite (both proprietorially sold as Campden tablets) to remove chloramine from brewing fermented beverages. However, residual sulfite can cause off flavors in beer so potassium metabisulfite is preferred. Sodium thiosulfate Sodium thiosulfate is used to dechlorinate tapwater for aquariums or treat effluent from wastewater treatments prior to release into rivers. The reduction reaction is analogous to the iodine reduction reaction. Treatment of tapwater requires between 0.1 and 0.3 grams of pentahydrated (crystalline) sodium thiosulfate per 10 L of water. Many animals are sensitive to chloramine, and it must be removed from water given to many animals in zoos. Other methods Chloramine, like chlorine, can be removed by boiling and aging. However, time required to remove chloramine is much longer than that of chlorine. The time required to remove half of the chloramine (half-life) from of water by boiling is 26.6 minutes, whereas the half-life of free chlorine in boiling 10 gallons of water is only 1.8 minutes. Aging may take weeks to remove chloramines, whereas chlorine disappears in a few days. References External links Chloramines in Drinking Water at EPA Citizens Concerned About Chloramine (CCAC) Water treatment Chlorine