Modern toilets often have two flush buttons, but many people don’t know they have more than one use. These buttons help save water: the bigger button uses about 6-9 liters for solid waste, while the smaller one uses 3-4.5 liters for liquid waste. Using the right button can save a household up to 20,000 liters of water a year compared to toilets with just one flush option. Although installing these toilets may cost more at first, they save money on water bills and are better for the environment. The idea, introduced by Victor Papanek in 1976, was first used in Australia in 1980.