System and method for conditioning water. In one embodiment, a softening membrane selectively rejects hardness ions in a supply of water. In another embodiment, the softening membrane is used in conjunction with a purification device configured to remove impurities from a portion of output flow of softened permeate water. In a third embodiment, the softening membrane is used in conjunction with a conditioning agent dosing unit configured to supply at least one conditioning agent to an input flow of water entering the membrane to prevent membrane fouling. In still another embodiment, a water quality monitoring unit is configured to monitor water quality of the output flow of softened permeate water and a portion of concentrate water recycled back through the softening membrane.