Leaky toilets can waste thousands of gallons of water each year. The flush valve at the bottom of the tank is usually the culprit. To test yours, place a few drops of food coloring in the tank and leave over-night. In the morning, check the bowl for dye. If it leaked, replace the flush valve. It costs only around $2 and replacing it is an easy do-it-yourself project.
Easy Way To Flush Out Leaks