Here's a great question submitted to AskAquaPro.com on Nov 3, 2009.
Ron Whitworth asked;
"Can I make my existing toilet more water efficient rather than throwing it away?"
Well Ron the short answer is, I hope you can.
I am a big fan of minimizing the amount of waste that goes into our landfills, and converting/upgrading your existing toilet rather than throwing it away is one thing I definitely encourage; under the right circumstances. There are plenty of “do it yourself tricks” out there that can be much more trouble than benefit so do your home work before deciding on what will work best for you. The good news is there are viable, effective, affordable options for improving the efficiency of a toilet rather than throwing it away and spending $$$ for a new High Efficiency Toilet (HET or UHET).
A couple things to consider;
a) If the current toilet uses more than 3.5 gallons of water per flush you should bite the bullet and get a new toilet. You will recover the cost of buying a new toilet pretty quickly by replacing these old water hogs. Get rid of it.
b) If you have a pressured assist toilet it can not be modified.
One of the most cost effective ways to improve water efficiency in a toilet is to convert it to a dual-flush. The Dual Flush Pro toilet conversion kit makes this easy to do and cost’s less than $55. This kit comes with everything you need to turn your existing toilet into a Dual Flush water saver toilet in about thirty minutes. The handle has a dual function; push one way for ½ flush to remove liquid waste and push the other way for full flush to remove solid waste.
For most major brand 1.6 gallon per flush toilets the kit is pretty well set up right out of the box to provide a 0.8 gallon half flush and 1.6 gallon full flush. Not all toilets are created equal. Some models will require adjustments to the factory settings of whichever kit you decide to use. These adjustments are simple with the Dual Flush Pro kit.
Thanks for asking,
Aqua Environmental Resource Center