Totally pure water is actually toxic to the human body. Pure water will rob the body of vital minerals and nutrients and that can cause severe health problems.
Totally pure water is what is know as hungry water and it will eat anything that it comes into contact with. Water is known as the universal solvent. It can dissolve any metal or mineral on the planet. Pure water is not living water and it will not sustain life.
Pure water and plastic do not get along at all. The toxic chemicals in plastic are leached from the plastic and into the water at a very fast rate. These contaminates have been linked to all kinds of health problems. For more information on this, look at the Bottled Water page listed below.