There must be more than a difference in the spelling as the de-ionised water
that I have bought here is as pure as distilled water and can be used
interchangeably in making photographic solutions.
The material you describe as containing sodium ions would appear to be
softened water rather than de-ionised. Although both are prepared using
ion-exchange resins. they are different.
When I was using pure water (long ago) we distilled it first, then put it
through ion-exchange to get higher purity.
Peter Marshall
On Fixing Shadows, Dragonfire and elsewhere:
http://faraday.clas.virginia.edu/~ds8s/
Family Pictures & Gay Pride: http://www.dragonfire.net/~gallery/
and: http://www.speltlib.demon.co.uk/
<< Most supermarkets here (don't know about where you are) sell gallons of
distilled water at prices much lower than the cost to make it yourself. As
to deionized (British: deionised) water, there are still salts in the water,
albeit soluble ones petermarshall@cix.compulink.co.uk (usually sodium) and even that adds some uncertainty to
the activity of the solutions. >>
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