as the names imply deionized water is water
that has been passed through a column or membrane to remove ions present. If
it is of the type used in homes, it is not truly a de-ionizer, removing all
ions, but rather an ion exchange column that exchanges polyvalent ions such
as Mg++ and Ca++ for Na+ ions. A de-ionizing column will not remove nonionic
organic substances from the water.
In contrast, distilled water is actually boiled in a still and the
condensate collected and distributed. Distillation removes both ionic and
nonionic organic contaminants.
Either method will require periodic regeneration, in the case of a
deionizer, or cleaning in the case of a still. I think you will have to
weigh the cost of maintenance and the required capacity needed before making