Aqua Rex is the only No Salt Water Softener with a U.S defined performance certification in the United States. This performance test was conducted on Las Vegas water in February of 2018. Residential unit for homes with Electric Heater or a Well water supply. Aqua-Rex doesn't use any salt or chemicals and it doesn't produce any environmentally unfriendly discharges. It needs no maintenance or servicing and it costs hardly anything to run. There is no chance of additional corrosion to your system. Aqua-Rex reduces scaling and also gets rid of old scale in the home. It partially softens hard water so you use less soap and detergents and there is no slippery feel to the water. It can deliver the same benefits of a water softener, and there in no salt to haul. Has 4 leads making it more powerful than the Gas model and able to effectively treat the Electric water heaters.