The versatile Big Berkey system is the ideal system for use at home with small or medium sized families, travel, outdoor activities or during unexpected emergencies. This powerful system purifies 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. Perfect for everyday use, outdoor activities and a must in hostile environments where electricity, water pressure or treated water may not be available. The versatile Big Berkey system removes viruses, pathogenic bacteria, cysts and parasites and extracts harmful chemicals such as herbicides, pesticides, VOCs, organic solvents, radon 222 and trihalomethanes. It also reduces rust, silt, sediment, foul taste and odors and unhealthy minerals such as lead and mercury. This system is so powerful it can remove red food coloring from water without removing the beneficial minerals your body needs. Virtually no other system can duplicate this performance.