How to make your old toilet a low-flush model on the cheap
Here's an easy way to save water at home ... Put a plastic bottle filled with pebbles in your toilet tank.According to Earth Easy, here's how it's done. Put an inch or two of sand or pebbles inside each of two plastic bottles to give them weight. Fill the bottles with water, screw the lids on and put them in your toilet tank, away from the operating mechanisms of the tank. Be sure at least 3 gallons of water remains in the tank so it, uh, well, flushes properly.
Note, this applies to older toilets as many new models are already low flush, using between 1 to 2 gallons per flush instead of the old 3 to 5 gallons, so check your toilet before you do this!












