4 oz Purogene Water Storage Treatment - This EPA approved water storage treatment works to disinfect potable water storage tanks, and treat water for long term storage by destroying existing bacterial colonies and preventing the development of new ones. Purogene eliminates bad odor and bad taste as well as destroying deadly microbes, bacteris, parasites and viruses ensuring you have great tasting water for coffee, tea, punch and other drinks. It will work in all types of water systems: cold water, hot water, plastic tanks, fiberglas tanks and metal tanks. 1 oz of Purogene per 30 gallon makes the water safe to drink for five years or longer. 4 oz bottle.