water filters in Ionizer

source: http://www.alkalizingnutrition.com/Alkaline-Water-Ionizers/Biostone-filters.html

Notice Calcium Carbonate layer in this filter. Helps in remineralizing the water, before it is ionized. As it is very difficult to ionize de-mineralized water....All water ionizers are remineralizing their water, before ionizing it. Makes sense. Ionization  of distilled, RO or pure filtered water will not work well.