If you have an older toilet with a 5 gallon tank, there’s an old trick that you can use to convert it to use less water. By simply filling a half gallon container and submerging it in the tank, you can cut your toilet water usage by 10 percent or more. Lifehacker’s Gina T. points us to a wikiHow artcile on the topic:

If you, like most Americans, flush 5 times daily, your family of 5 will save 350 gallons (1325 liters) of water every month [2]. These savings will significantly cut your water bill, too.

Adjusting the tank volume will affect your toilet’s ability to flush more, uh, serious business, so your mileage may vary. A lot of folks have a second bathroom that’s used more often for lighter work, in which case this hack could save quite a bit of water over a year’s time.

How to Convert Any Toilet to a Low Flush Toilet – [via] Link