If you leave a glass of water beside you at night and you drink it in the morning, you are making a huge mistake.
Although the ordinary water, unlike food, contains no sugars, protein and fat, it is easiest to contaminate by germs. Therefore, the water in the morning has a different taste of the night before.
If the water has been exposed for long to the air, it absorbs little carbon dioxide, and a small part of it is converted into carbonic acid. Additionally, the water collects deposits of dust.
Possible consequences of this include diarrhea, cramps and other stomach problems, so drink exclusively fresh water.
Another important thing – never fill a plastic bottle with water, because many of them are meant to be only used once. Better option is to buy a glass bottle and wash it frequently.