First Filter: Is Activated Carbon With Silver Carbon Granuels Which Reduces Chlorine, Thms, Organic Chemicals And Unpleasant Odors And Clouds Second Filter: Is Zeolite Infrared Bioceramic Balla Which Removes Heavy Metals Third Filter: Is Silica Sand Which Removes Acidic Components Of Water To Help Bring About Ph Balance Fourth Filter: Is Mineral Sand Which Has Plenty Of Mineral Supplements The End Result Is Pure, Crystal Clear Mineral Water