Best for: all dissolved ions - positive or negative, including those which cause hardness, alkalinity, acidity, also lead and other toxic heavy metals
May help with:
sediment, turbidity
Not for: organic chemicals

For all practical purposes, deionized water is “pure” water, as pure as distilled water.  It’s good for steam irons and car batteries and makes a great cup of coffee!

Deionizers are complete “ion exchangers”.  In a deionizer, water flows through a chamber filled with “cation” and “anion” synthetic resin beads.  Millions of hydrogen ions (H+) are loosely attached to each cation bead and hydroxide ions (OH-) are attached to each anion bead.  Passing water exchanges all its positive ions for H+ ions and all its negative ions for OH- ions. 

Released H+ and OH- ions react with each other, forming H-OH or H2O, which is water.

When deionizer resin becomes saturated with ions, it is either thrown away or, in the case of large commercial deionizers, “regenerated” with an acid and a base and used again and again. Water's ion content is usually expressed as “total dissolved solids’ (TDS) in grains per gallon (gpg).

Removed by Deionizer   Removed by Softener


Ca++ calcium  Ca++
magnesium Mg++   magnesium       Mg++
manganese  Mn++  manganese   Mn++ 
iron  Fe+++ iron Fe+++  
potassium K+
sodium   Na+  
lead                       Pb++
carbonate    CO3=
bicarbonate HCO3-
sulfate  SO4=
nitrate        NO3-

Richard Kunz, chemist
719 635-1325