Drinking pure water for a long period of time has certain hazards. Pure water is natural water that has been processed, purified and cleaned through a number of procedures. After multiple processes, pure water removes substances and bacteria that are harmful to the human body, as well as mineral elements that are essential to the human body. Long-term excessive drinking of purified water may lead to a lack of mineral elements, which is harmful to the body, because the mineral elements can constitute and repair human tissues, while providing the body with regulating substances to maintain the normal physiological functions of the body. The best choice for drinking water is plain water, which is safe, hygienic and easy to obtain, and the process of drinking plain water in moderation is also a process of hydration for the body, while supplementing the body with essential minerals.