Posted on April 18, 2013 Put food coloring in your toilet tank to check for leaks. If you have a slow leak in your toilet tank, hundreds of gallons are just slowly and silently cascading down the side of your toilet bowl every month. Fortunately you can easily detect if the uptick in your water bill is from a slow leak or not. Simply put the food coloring into the toilet tank and wait for about a half hour, if it seeps into the toilet bowl, you have a leak. Fortunately it’s an easy fix and can save hundreds of gallons of water a month. Call Deer Valley Plumbing Contractors, Inc. at (602) 497-4806 and we can take care of that leak immediately.