I work for a university and they recently retrofitted all of the toilets to dual flush toilets which will save the school thousands on their water bill. You pull the lever up for a low .8 gallon flush and pull the lever down for a 1.6 gallon flush. Most toilets made before 1994 have flush sizes of 3.5 gallons and up, so you can imagine the savings.
I was thinking I should do this for my house. The school used an industrial dual flush kit, but I have found several dual flush kits for residential toilets. They all look relatively easy to install. The dual flush kit is a great way to save money and water. If you've got an old toilet that needs replaceing you might be better off upgrading to a new dual flush toilet.
I plan to pick up a kit and install it this weekend. Here are some of the ones I have found online that I am considering. Would love to hear from anyone who has used them!
Here is one warning that I saw on the Building Design + Construction
http://www.bdcnetwork.com/article/CA6674582.html?rssid=203
website which warned that improper use might result in more water waste, sinced the dual flush kit is not designed specific to your toilet it may alter the settings a bit, so you could end up double flushing--wasting more water. Just something to note.
