Rainfresh two tank water softeners make water soft by removing hardness using a process called Ion Exchange. Hardness-causing calcium and magnesium ions are replaced by an equivalent number of sodium ions. Sodium ions do not form scale, thus making the water soft, while maintaining its chemical balance. By installing a Rainfresh 2-Tank water softener, your laundry will come out cleaner and softer, you'll get spotless glasses and dishes from your dishwasher, enjoy softer bouncier hair and smoother skin after showers and prevent scale build up in your bathroom and water heater. Rainfresh two tank water softeners have a separate salt (brine) tank which makes salt-filling much easier. They are also easier to service due to easier access to the control valve.