What's an easy and inexpensive way to modify a toilet so that it conserves water?
Matt Hickman has some updates on the old brick-in-the-tank trick.
Q: My husband and I are about to embark on a few budget-minded water- and energy-conserving home improvement projects around our home. First stop? The bathroom. Ultimately, we’re interested in replacing our antiquated toilets that use 3.5 gallons or more per flush with low-flow 1.28 gpf or dual-flush models but financially that’s not in the cards at the moment. Do you have any recommendations for temporary, DIY-friendly (we’d rather not resort to calling a plumber) ways to make our commodes more conservative while we save up for the real deal? 
Comments
Do not replace your functioning toilet with one of these low flow debacles. They work poorly (do the research), and what is worse, they do not actually conserve much more water than the toilet you already have (easy to Google this.)
You have a working toilet. Don't swap it out for one that does not work, and does not come with any other benefit.
had a landlord who had done this to 2 different toilets in hte house about 3 years prior to us moving in. twice the tank seperated at the small hole that is sits on the base at. once with my wife and a second time on the deveolpmentally disabled gentle man who we cared for. both times the merely shifted to "finish the Paperwork" on their "deposit transaction" both were on opposite ends of the wi=eight spectrum 1 approx 112lbs the other approx 225lbs. both were left sitting in a pool of water.... More
pee in the shower can save a flush per person per day
A problem with reducing the water in your toilet tank, either by just lowering the fill level or by putting an object in the tank, is that by reducing the amount of water in the tank you reduce the pressure available to make the toilet flush. Dual flush toilets have two flushing cycles, one that uses a relatively small amount of water (for #1), and one that uses the full tank (#2). New dual flush toilets are quite expensive, but older toilets can be converted to dual flush economically. At.... More
That was supposed to say:
At our store, Greenward, in Cambridge, MA, we carry the One2Flush...
If your guests don't mind, stick to the ole' saying if it's yellow let it mellow, when it's brown, flush it down.... Works everytime!
I recently had to replace the float assembly in one of my toilets.
The one I used helps me save water in three ways:
1) Similar to the brick-in-the-tank trick, the new float assembly allows me to set how high the float goes before the water stops.
2) I was pleased to find that you can now get one with a valve on the bowl filler line. It helps ensure that your bowl doesn't fill up before your tank - because every drop after that point just goes straight down the drain..... More
