Ice Machine - Use soft, or untreated water?

I have just got an ice making machine (Whirlpool K20)

Now, I am unsure if I should use water directly from the mains, water from my water softener (the type that uses salt) or filtered water in the unit.

I live in quite a hard water area (Orpington, Kent)

Using soft water will obviously stop the machine getting scaled up, however, I didn't think it was good to drink soft water (we don't)

using filtered water will remove any nasties in the water, but I don't think it will stop the scale

using soft, filtered, or filtered soft water would be impractical, as it would mean I would have to re-plumb things! (Although, if soft, then filtered is the way to go, I could get another filter for the ice machine I suppose.)

Thanks for any advice!

Sparks...

As part of one of my jobs(!), I install and service ice making machines that are in use commercially. They are not allowed to be connected to the output from an ion exchange water softener, due to the saline levels in the water, so I have no experience of what a softener would do to the internals of the machines.

I have dismantled a number of machines over the years which have been directly connected to a tap water supply. The inner surfaces of the machines, where they are immersed or splashed by the water, get covered with an unpleasant slime, something like a thinned down vaseine. When this builds up sufficiently to begin to break away, it attaches itself to the ice cubes, which is not pleasant. It also is a time consuming job to try to remove it all from the various nooks and crannies within the machines.

All the machines that I install are fitted with in-line activated carbon cartridge filters, which are changed usually annually, and this prevents the above problems.

I have never seen an ice-maker with an undue amount of scale within, as, in general, there is little evaporation taking place throughout the machine's cycle...