[quote]Caffeine, alcohol, may not count, since these are diuretics, and have to drink more water drinking these due to the frequent urination. With chemo you need more water to flush the toxins out of the kidneys.[/quote]What is the story on things like tea and coffee, that are considered diuretics? I know they make one pee a lot but is much of the liquid bypassing getting into the body that is good for hydration?

For example, a liter of saline puts a liter of saline into the body. A liter of water consumed orally puts a liter minus x, and it appears a liter of tea puts a liter minus (x+Y) into your system.