The old folk wisdom that says place a brick in your toilet's water tank is partially correct: It's an effortless way to save water, but a brick isn't the best choice of object. Use a plastic bottle filled with water instead.
Don't worry, you don't have to turn hippie and "let it mellow if it's yellow" in order to save clean water which is an increasingly scarce resource. Most toilets will flush perfectly well with a little less H2O. The average model uses three to seven gallons per flush. A bottle in the tank will displace enough water to save half a gallon to a gallon each use, or up to about 10 gallons a day in a typical home.
All you have to do is drop a little sand or some pebbles into a bottle, fill it with water, and put it in the tank, making sure not to disturb the toilet's working parts. Many toilets flush well with a submerged 2-liter soda bottle, but experiment to find out what size bottles fit best and produce the best flush.
What's wrong with a brick? They have been known to disintegrate in toilet water over time, leading to damaged plumbing. If you are a mason or otherwise determined to use a brick, wrap it in a sturdy plastic bag first.
You can also look for kits at local home improvement stores to convert American-style flushers to European-style dual-flushers, offering a half-flush option for liquids ($20 at homedepot.com). When it comes time for a new toilet, look for one with a WaterSense label. And, of course, be sure to fix leaks, which can cost $20 or more in wasted water.
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