DE-IONIZED WATER D009
Water can be soften and purified with ion-exchange agents which may be specially prepared synthetic resins.
Cation-exchange agents substitute sodium for calcium and magnesium ions, and produce soft waters. This is how a typical home water softener works.
When the water is treated with a hydrogen derivative of a resin, the metal cations form acids from the salts. The carbonates are converted to carbonic acid which goes off in the air. When it is treated again with a basic resin derivative, or anion-exchange agent, the acids are removed.
Water receiving this double treatment is equal to distilled water.
You should be aware that there are instances where some di-ionized water has been know to chemically attack carbon seal faces. If you run into this problem you will have to use two hard seal faces. Tungsten carbide against Alpha sinterd silicon carbide would be a good choice.