Dual flush toilets are used widely throughout Australia, Asia, and Europe. Conversion to high-efficiency toilets like dual flush models or composting toilets is proving slower going in the United States. The pros and cons of these water-efficient and environmentally friendly "green" toilets that offer two flush volumes must be weighed when deciding whether it's worth it to abandon the standard flush system and go for either a full fixture replacement or a dual flush toilet conversion, also known as a retrofit. Pro: Dual Flush Toilets Save Water A dual flush...