New tablets should store approximately three years. Some estimates are shorter if the bottle has been opened. Water purified with chemicals may still look ugly and smell bad,straining through a cloth is recommended, especially if the water is cloudy. You may need a waiting period to ensure potable water. The PentaPure system, with Products such as the Water Jug and Oasis,use a chemically treated resin bead that water passes through.
Water is then safe to drink.
The second way to treat contaminated water is with water filters. With this method, you are able to drink the water instantly. Ceramic filters, like the Swiss made Katadyn filters. Harmful bacteria like salmonella, shglia and E. Coli, and protozioas like giardia and cryptosporidium are mechanically removed form the water as it passes through the filter. These filters are all so treated with silver to prevent bacterial growth.