Gerber's Ultra Flush high-efficiency toilet uses only 1.1 gallons of water per flush and can decrease a homeowner's yearly water expenditure by 40 percent, the company says. Using the standard water supply, the unit pressurizes the air inside the tank and forces water into the bowl. It's available in a variety of styles, colors, and rough-in sizes. Gerber Plumbing Fixtures, 630.754.0278;