It's a leaky business.

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If your water bill is slowly increasing with no culprit in sight, a leaky toilet might be to blame. If your toilet tank were leaking water from the tank into the bowl—slowly, subtly, silently—you'd never know. A leak might not sound like a big deal at first, but the results over time can be pricey. Leaky lost gallons quickly add up and could cost you hundreds of dollars. According to NYC Environmental Protection, while a small leak could waste 30 gallons per day (which would cost you 40 cents each of those days), a large leak could waste up to 4,000 gallons per day, which adds up to $53 per day.

But! We have good news. There's an easy way to check for a slow leak, and you have the tool you need in your kitchen cabinet. Delve into your collection of food coloring bottles, pick a color—any color—and prepare to test your toilet. All you need to do is place a sufficient number of drops of food coloring into the tank. There should be enough to visibly tint the water, but not so much that the water is opaque. Fifteen to twenty drops should do the job.

After dyeing the water, wait thirty minutes, read the latest issue of Southern Living, listen to a podcast, and return. Check the bowl; if you see that any of the food coloring-dyed water has made its way into the bowl, you'll know there's a leak between the tank and the bowl. It's as simple as that.

Lowe's even has a video tutorial to walk you through routine maintenance and checking your toilet for leaks, which you can see on their website. According to them, the leak indicates an issue with a flapper or fill valve, which a plumber can help you repair or replace.

Check out some of our other money-saving tips for the home, plus how to clean your toilet with Coca-Cola. Also be sure to bookmark our home maintenance checklist to help you keep your space in tip-top shape.

WATCH: The Best Way to Clean a Dirty Toilet Can Be Found Right in Your Fridge

Have you tried the food-coloring test to identify leaks in the bathroom? It's a smart do-it-yourself trial that, in the long run, can save you from a rising water bill.