The best hard water softener for bathroom »  decreases the amounts of calcium and magnesium in the water, avoiding the formation of limescale on fixtures and tiles. prolongs the life of plumbing, improves skin and hair, and increases soap lather. The best models give options for both salt-based and salt-free salt, require little maintenance, and are simple to install. Large grain capacity and efficient renewal cycles are desirable, as are small-space or under-sink compact designs.