Changing Habits

I am desperately trying to wean my adult son of some of his college habits.  He started drinking lots of Mountain Dew and Coke in college as he was studying.  Now that he has passed  his CPA exams I feel it is the right time to work on this process. 

He has been living at home for over a year now and I have been observing his habits and his does like to drink.  He does not like to drink water.  He drinks milk, orange juice, coffee, soda and anything else that comes in a container.  He drinks my lemonade if I make it however he will not make it for himself. 

I have two college refrigerators in my garage in the summer so I decided to make large quantities of lemonade for the week and keep it in the refrigerator.  I reused some jars that I cleaned out from spaghetti sauce and I poured the lemonade in them.  This is working great.  It has count down on the amount of soda he is drinking.  

Right now I am using Crystal Light, however I would like to find something healthy.