Best thing we did was have a water filter installed. The kettle doesn't fur up at all, unlike bottled water that all used to fur up the kettle, some brands more than others. We got a local plumber to fit and the recommendation says to change the filters every 2 years. However, my husband suggested that we change the filters when we see furring in the kettle, which makes sense to me. We have had the filter system 3 years in January and no furring noted in the kettle yet, hence we haven't changed the filters. The water tastes good, so we are continuing to watch carefully.
I hope this is helpful
Sue