Abstract: A method for treating feedwater is provided. The method includes steps of introducing a treatment composition into a feedwater stream to provide a treated feedwater stream containing scale inhibitor at a concentration of at least about 0.1 ppm, and combining the treated feedwater stream with a detersive composition. The scale inhibitor can include a phosphate scale inhibitor, a carbonate scale inhibitor, or a combination of a phosphate scale inhibitor and a carbonate scale inhibitor. The detersive composition can be provided as a cleaning composition, a rinse agent composition, or a drying agent composition. A treatment composition and an apparatus for treating feedwater are provided.