Have used several of these units in the past and they do the job. Understand they are NOT water softeners in the typical sense. But they DO eliminate calcium buildup on faucets and dishes, and inside your hot water heater. I live in the desert using well water with Total Dissolved Solids (TDS) over 500 ppm. I use charcoal filters to enhance the taste but I have zero calcium buildup in my pipes, faucets, and shower head.