Ever hear that faint hiss of water in the middle of the night and just ignore it? I did, for months, until a water bill showed up that was noticeably higher than usual. A running toilet is the silent budget killer, and the fix is usually five minutes.

The flapper is the usual culprit

Open the tank and you will see a rubber flapper at the bottom. It lifts when you flush and drops back down to seal the tank. When it warps or gets gunk on it, it does not seal completely, so water leaks past it into the bowl all day.

How to check and fix it

1. Drop a few drops of food coloring into the tank and wait ten minutes without flushing.
2. If the color shows up in the bowl, the flapper is leaking.
3. Turn off the water, flush to empty the tank, and pop the old flapper off.
4. Snap a new one on and hook the chain back up with a little slack.

A new flapper costs a few dollars and takes one trip to the hardware store. While you are in there, check the chain length. Too short and it holds the flapper open, too long and it gets caught underneath.

The food coloring test is the part I wish someone had told me years ago. It turns a guess into a straight answer in ten minutes.