Is there such thing as too much fluid? I really dont know exactly how much my 21mo old drinks, but most of his cups are probably 10 oz sippy cups. He probably drinks 5-9 of them a day. Most of which is water, sometimes a little juice at the bottom w/ water and milk. He eats fine, but I dont know if he is filling up on too much liquid and should be eating more food? Anybody have any idea? Thanks