Water is the source of life, the earth is because of the water, there is the breath of life. The book of wisdom integration – Spring and Autumn Yuan life package “said”, “water, heaven and earth, the curtain, the beginning of the five elements, the birth of all things, the essence of the essence of the liquid”. China is a water-scarce country China’s total water resources of about 2,800 billion m3, accounting for 6% of the world’s total water resources, ranking 6th in the world. However, the water resources per capita possession is only 2100m3, which is only 28% of the world per capita level, and is listed as one of the 13 countries in the world with poor water resources per capita possession. More than 300 of the 657 cities in the country belong to “severe water shortage” and “water shortage” cities according to the evaluation standard of UN-Habitat. For example, some provinces in the north, such as Gansu, Shaanxi and Shanxi, there is even an extreme water shortage. Food is not as good as water. According to scientists, people will drink 50 tons of water in their lifetime, the ancients said: “medicine is better than food, food is better than water, water is the king of all medicines.” But the World Health Organization (WHO) survey shows that: 80% of the world’s diseases and 50% of child deaths are related to contaminated drinking water. Therefore, the primary problem of drinking water is to drink healthy water. Tchaikovsky’s story On the evening of October 20, 1893, after watching a play, Tchaikovsky went to a restaurant for dinner with several friends and relatives. He ordered macaroni and cheese, white wine and mineral water. At that time, the law already stipulated that water for drinking in restaurants had to be boiled before it could be served to the guests, because there was a cholera epidemic in Europe at that time. But the waiter told him there was no boiled water, so Tchaikovsky insisted that he bring cold, unboiled water. His companions advised Tchaikovsky not to drink cold water, but he didn’t listen and drank it as usual, and then he had belly pains and diarrhea all night long. The cholera that allegedly took Tchaikovsky’s life was caused by the unhealthy cold water. What is healthy water Therefore, the World Health Organization (WHO) put forward the concept of “healthy water” and the seven criteria for healthy water: 1, does not contain any harmful and odorous substances, especially heavy metals and organic matter. 2, the water is moderate soft hardness, between 50 ~ 200mg / L. 3, is weakly alkaline, pH between 7.0 ~ 8.0. 4, the proportion of trace elements and the proportion of mineral content in the water is moderate, similar to the normal body fluids. 5, the content of dissolved oxygen and carbon dioxide in the water is moderate, the water dissolved oxygen ≥ 6 ~ 7mg / L. 6, the water molecular group is small, the bottom half width of the nuclear magnetic resonance spectrum is not greater than 100Hz. 7, the nutritional physiological functions of water (including solubility, permeability, diffusion, metabolic power, emulsification and detergent power, etc.) to strong. “Diet, the lifeblood of man also”, so far, there is no one substance can replace water. The ancient people of China also believe that the ground water source is generally selected from a long stream of water, that “the long flow of water together with a thousand veins and not exhausted, the many dirt and not dirt”, groundwater to “far from the earth’s veins to the top”. How to identify the quality of water The method of identifying the quality of water, “the regulation of disease diet,” it is recorded: “the first should be defended taste, taste sweet and light for good, salty and for stone gas, mud gas for bad. Second on the color, the color is clear as crystal is good, white as rice slop and although the face of the clear red, yellow, purple foam for the inferior”. How much water to drink is considered adequate The Chinese Dietary Guidelines for Residents (2016) points out that to drink an adequate amount of water, adults 7 to 8 cups per day (1500-1700ml), in high temperature or physical labor conditions, but also need to increase the amount of water. In addition, dietary water, such as water in food, soup, porridge, milk, total daily water intake should be between 2700-3000 ml.