The invention relates to systems and methods of treating water by directing the water to a first reverse osmosis (RO) membrane; separating the water using the first RO membrane; adding a chelating agent to first permeate and/or raising the pH of the first permeate to between about 5.5 and 7.5 before a second RO membrane; and separating the first permeate into a second permeate and a second concentrate using the second RO membrane, thereby separating constituents from the water.