Actually, removing calcium and magnesium from the water has little effect on the quality of ice prepared in the home. Here again, the reason is that softening the water does not reduce the total mineral concentration.
For example, to the extent that a softener removes sediment, iron and manganese from water, this would help to produce a least cleaner ice.
Filters, of course, can be helpful in removing iron, turbidity, tastes and odours from water used for ice-making.
The use of polyphosphates is an economical method of treating water used in typical restaurant ice-making units. The polyphosphates keep the minerals in the water dispersed and in this way minimize the cloudy appearance of ice cubes.
If fed in proper concentrations, polyphosphates also control scale formation and corrosion in the ice cube machine. Approximately 5 ppm are recommended for scale prevention and 10 ppm for both scale prevention and corrosion control.