Distilled Water

• The most common forms of water distillation involve cooking a source water (usually tap water) to produce a water vapor. This water vapor is captured and cooled to form a condensate. The condensate is distilled water.
  This process separates out pure water from disinfectants in tap water such as chlorine or chloramines, as well as dissolved minerals, flouride and other trace elements found in municipal water sources.
  This pure water readily takes ions from its surroundings, leaving a slightly ionic, less aggressive form of purified water.
  
  

Distillation Methods

• Any method of stimulating water vapor from a water source can be used for distillation. Electric heaters or steam heat exchangers are common.
  Placing a source water into black painted pans exposed to sunlight is a "green" method of turning gray water or salt water sources into vapor for condensation.
  None of these techniques attempts to isolate the water vapor from possible ionic sources. Ions picked up during the condensation phase tend to stabilize the final product.
  
  

Deionized Water

• As the name states, deionized water is water free of ions.
  The most common ways to produce deionized water are to heavily filter a clean source water. Longest filter life is gained by using the purest source water available, so deionized water is often made from a distilled water source.
  
  

Deionizing Methods

• The most common method for producing deionized water is to pass a relatively pure source water through a Reverse Osmosis (RO) filter. RO filters trap waterborne particles as small as one angstrom, passing through a deionized product while stopping even waterborne metallic and organic ions.
  Resin-based "polishing" beds are also used in commercial and industrial deionized water production plants, to "catch" any ions passed in purified (usually a distilled water base) water.
  
  

Effects on the Body

• Distilled water is condensed, pure water with trace elements dissolved into it. It is less healthy to drink than tap water as it will rob the body of essential salts and nutrients.
  Deionized water is pure water with little or no other elements included.
  As a result, each will leach ions from any surrounding vessel, including a person's mouth, throat and digestive system. This leaching action will damage soft tissues and harm the drinker.
  As deionized water is more completely stripped of ions than distilled water, it will more aggressively leach ions from a body. Therefore, deionized water is even less healthy to drink than distilled water.
  Most deionized water is used in industrial processes where water's solvent characteristics are desired, and the aggressive end of water's range is worth the handling risks. Risks include the leaching of salts and oils from the skin and eyes of the handlers, however, this requires prolonged and extensive bare skin contact. The risks are much less than those from similar contact with any other washing acid or chemical solvent.