The book is a serious study and at the same time a fascinating narrative dedicated to the problem of drinking water quality. The author pays special attention to methods of water purification at home, evaluates the effectiveness and usefulness of filters offered by domestic and foreign companies. While working on the book, the researcher collected information about the quality of drinking water in different regions of Russia and received advice from leading experts. The book will be of interest to anyone who cares about their own health, which, as we know, is directly related to the quality of drinking water.