· A modern water softener stops the damage at the source. At its core, a water softener performs a simple exchange—an ionic “swap meet” of sorts. How to Install a Water SoftenerIt might look intimidating at first glance, but modern plumbing fittings and well-designed kits have made the process of installing a water softener an easier task than perhaps it once was. For this project, I installed a smart water softener, which is a cabinet-style unit designed for mid-size households. It should sit near the main water entry point so that the water is treated before it moves through the rest of the house.