I used to buy Capri Suns for my kids, but my DS3 could go through two whole boxes alone a day if you let him! Obviously this is way too expensive, and way too many calories for their little bodies, so I have been buying Wyler's Lite. Costs about $2.20 for 6 pitchers (cheaper and tastier than Crystal Light, IMO) and you dont need to add any sugar like you would Kool-Aid. Hardly any calories, so I let them drink that all they want, as well as milk, juice and water. I tried to give my DD5 a water bottle with our home-made drinks for her snack in kindergarden to save money, but she just never screwed the lid back on tight enough and would always come home to a mess. I buy the Capri Sun waters for her (very low calories there also), but they are strictly for her to bring to school, so I am not paying too much for those (I always find them buy 3, get 1 free too!)