I am a big water drinker. I thought I could get by with filling up my bottles with water from the fountain, but after the first day, my stomach was very upset. I didn't notice a different taste, it just didn't agree with me. So we now go to publixs and buy a couple of gallons of spring water and fill up the bottles and keep them in the collapsable cooler in our room. this works great for us and the cost is extremely low. About $1.69 per gallon.