Lisa, My son who is 22 months old and weighs 27 pounds (salt wasting) also drinks a lot of fluids (about 60oz per day). He drinks two cups of milk during the day (of which I add the salt), the rest of the day and night he drinks water. Sometimes I fill his eight ounce bottle three times at night. I am afraid to wean him off of his bottle for fear that he won't drink enough water in his cup (He takes only water in the bottle and juice and milk in the cup).