Hello...
I live in a hard water area..which has its problems..
We've just had a new dishwasher and want to protect it as much as possible from lime scale build up..some people suggest calgon...others avoid...
Is there anything other than fitting a soft water filter...
when I iived in Norwich I had a filter fitted to the incoming cold water suppy it was a column thing under the sink that had a carbon type filter which was changed every 6 months or so...
If you wanted to take a belt and braces approach you could always fit an inline filter to your dishwasher supply. It will be cheaper than most 'built in' filters and would 'Filter your Filter' so to speak !
I forgot to mention in my original reply that dishwasher cleaner is a good thing to use every few months. I always thought they were a gimmick but a friend of my daughter, who is in the repair business, said they're a good idea, so now I use one regularly.