I hear what you guys are saying about making sure it is tight enough.. but we have had the opposite problem we were having to unscrew ours because when we tightened them all the way they leaked. The bottle would be a good bottle if the thing in the bottom would hold up. They are just not worth the time if you can find a good bottle you dont have to be thinking about all the time, expecially when you are in the car or on the go!