Retrofitting to make your toilet use less water - Sunset Water Watch 1991

Fiddling with your existing toilet to make it more water efficient will be successful only if it still functions properly once you've made your adjustments. What does that mean? Simply that once you've installed weighted jugs of water, or displacement dams, or dual-flush mechanisms, or early-closing flappers, or whatever, you should still have to flush only once to clear the bowl.

The best way to alter your toilet to conserve water depends on your toilet's present efficiency. If a full flush barely clears the bowl, you're better off using a dual handle mechanism or replacing the toilet with an ultra-low-flush model. But if the toilet seems to use more water than it needs to, you can choose from a new generation of retrofit devices that will decrease the amount of water used per flush while still letting your toilet work the way it was designed to. How to flush with less water When you depress the handle of a typical toilet, gravity makes the water in the tank rush into the bowl, creating the siphon that carries the waste down the drain line. A standard toilet is, in theory, engineered to work with the force that its tank water generates; a toilet with a 5-gallon tank works most efficiently when the pressure of 5 gallons rushes into the bowl, through the trap, and down the line. When water wasn't an issue, designers allotted more water than the toilet really needed to operate, just to make sure it always worked properly. With those designs, displacement devices (jugs of water, tank dams, bricks) can save you a significant amount of water per flush without decreasing the efficiency of the toilet. But if you install one of these first-generation water-savers in a more efficient model, you'll likely have to flush more than once to clear the bowl; that's because they essentially make the tank smaller, so less water rushes into the bowl, and with less force. In this case, another retrofit mechanism may be the solution. Unlike displacement devices, the best of the new retrofit water-savers don't reduce the force of the water rushing into the bowl. Variable-buoyancy flappers and dual-handle mechanisms keep your toilet flushing with the weight of the water it was designed to use while still saving water. (Another new device rides the overflow tube and forces the flap to close, but it may not fit all toilets.) Variable-buoyancy flappers are designed to make the valve between the tank and bowl close before all the water rushes out of the tank. The water that goes through still moves with its designed full force. If one of these devices is put into a 5-gallon toilet and adjusted to save 2 gallons, all 5 gallons are still moving downward as the flush starts, but the flap closes while 2 gallons remain in the tank. Dual-handle mechanisms work in a similar way, but they give you a choice. You can use the full flush with one handle, or use a second handle that releases up to 75 percent less water-still enough force to carry away liquid waste. The new flaps and dual-flush units range in price from $5 to $30 or more; some water districts will send you parts free.