Reduction of water hardness was up to 100 times more effective at stain removal than increasing detergent dose or washing with hotter water, according to a March 2011 study by Scientific Services S/D on behalf of the Water Quality Research Foundation.The study adds more data to a laundry list of benefits for softened water. Another 2011 study conducted for the Water Quality Research Foundation assessed the impact of water hardness on automatic dishwashers, finding a similar effect in the kitchen as was observed in the laundry room.