Modern dual-flush toilets use two buttons to reduce water waste. As the article explains, many people “don’t fully understand” how the system works, even though it’s meant to use only the amount of water needed for each flush.

The two buttons serve different purposes. The large button releases “between 6 and 9 liters of water” for solid waste, ensuring the bowl clears properly. The smaller button uses “only 3 to 4.5 liters” and is meant for liquid waste.

Since most daily flushes involve liquid waste, choosing the small button saves a significant amount of water. Estimates show that a household using the correct button regularly can save “as much as 20,000 liters of water” per year. This makes dual-flush toilets far more efficient than older single-flush models.

Although installation costs can be higher at first, long-term savings usually compensate. Lower water use leads to reduced monthly bills, offering both financial and environmental benefits that “accumulate steadily over time.”

Dual-flush technology isn’t new. The idea was introduced in 1976 by Victor Papanek and later put into practice in Australia in 1980, where water shortages encouraged adoption. Today, the system is widely used as more people focus on sustainable living.