Potable Aqua Chlorine Dioxide Water Purification Tablets 20 count - The most trusted name in water purification products, Potable Aqua is used by various militaries and relief organizations around the world. Potable Aqua products provide time-tested, simple-to-use water treatment options for campers, backpackers and other outdoor enthusiasts. Proven effective against bacteria, Giardia, Lamblia, Cryptosporidium, and viruses. No after taste-improves the taste and odor of water. 20 tablets treat 20 quarts.