Some of you may have a Berkey water purifier. It is touted as the best there is. From their wabsite: "Berkey® Systems are the World’s Most Powerful and Cost Effective Personal Water purification Systems Providing Reliable and User-friendly Water Purification in Both Normal and Hostile Filtration Environments." "Moreover, Berkey® systems are capable of purifying both treated water and untreated raw water from such sources as remote lakes, streams, stagnant ponds and water supplies in foreign countries, where regulations may be substandard at best. So powerful, this system is able to remove red food coloring from water without removing the beneficial...