How much water is too much per day?

Depends: The amount of water you should drink depends on your body size, how active you are, the weather, and your overall health. Check out this handy calculator at: http://nutrition.About.Com/library/blwatercalculator.Htm.

Water intoxication: To avoid overdosing on water (water intoxication), it depends on your kidney function. A healthy kidney can excrete about 1 liter per 1 hr. Try to stay under that to avoid intoxication.