Brewman, I am always fighting with my hubby to make the coffee with the untreated water. The minerals make the coffee more flavorful. I have an RO system on my drinking water in addition to the softener and that really makes lousy coffee. I have a solar hot water heater and just had to have a glass panel replaced. The solar guy said that with my unit being almost 20 yers old, my tank was probably ready to go. (It's stone lined but has copper coils and feeds to copper lines in the collectors). when he took a look, he was amazed. There was no build up of minerals or deteration of the tank...same with my summer winter hook-up (the hot water hookup) in my oil burner. So my softener paid for itself!