 [ Symptoms ] when can i stop using baby formula water for formula and start using either tap or jug water i buy for a water cooler  my baby is 3 months and we are still buying formula water i was wondering how long we would have to do this my husband and i drink water from a water cooler we buy replacement jugs for but it only comes out cold we also have city water which we cook with but do not drink [ Disease ] baby formula water i can not say that any of my little patients are using special water to mix the formula i see nothing wrong with mixing the formula with any bottled water just buy a gallon of purified drinking water leave it at room temperature and use that or use your water cooler water to fill up a jug so it gets to room temperature before you give it to the baby i do not think they would appreciate ice water i do not know the quality of your city water some cities have excellent water