If you've ever looked at your water bill and thought, "There's no way I've used THAT much," you might be right--and interested in saving money. But unless you hear dripping, it's not so obvious to tell if you have a leak. You could spend $100 or more on a plumber to check for you--or you could try this genius trick to see if your toilet's running up your charges, which Donnie Barrett of the Washington Suburban Sanitary Commission (WSSC) says is the cause of an unusually high bill 90% of the time.
Step 1: Flush your toilet; then, wait 5 minutes.
Step 2: Take off the tank lid.
Step 3: Add a few drops of food coloring to the water in the tank.
Step 4: Wait 15 to 20 minutes and then check out the bowl. If the usually clear water has taken on the hue of the food coloring, you likely have a leak.
Good news: you still don't have to call a plumber. The problem may be that the tank's flapper is no longer doing its job. But a replacement is easy to find and install yourself. It looks like the below and sells for as little as $3 at home improvement stores and online, though you should check that the one you're considering buying is compatible with your potty's make.
No color in the toilet after 20 minutes? According to the WSSC, an unused toilet may be to blame, and you should shut off the water to that toilet. See the below video for step-by-step instructions: