Thermos Guardian: Thermos bottles do a wonderful work of holding water cold. Having said that, we identified this individual bottle challenging to thoroughly clean, and it is made up of gaskets That could be much more susceptible to receiving moldy. I also keep mine next to my bed at night http://louisfpajr.izrablog.com/7442661/indicators-on-water-dispenser-for-5-gallon-bottle-you-should-know