Simple. No water is necessary.Fluid value in foods or other liquids can easily meet the daily hydration need.As long as they take in enough hydrating materials to pee every 6-8 hours and maintain normal activities they have done enough.
Silly. There is a common, silly, urban legend about "hydration". The amount of fluid required depends on the individual, the temperature and humidity, the activity, the diet. Consuming very large volumes of water to produce large volumes of dilute urine is a good strategy to manage urinary stones and urinary infections. But is is otherwise silly unless the person enjoys frequent, copious urination.
Just satisfy thirst. There is no right or wrong amount of water and you shouldn't worry about it. People without kidney, heart or certain liver disease problems needn't worry about how much. Just drink enough fluids so you're not thirsty, and you'll be fine. Read more...