The toilet flapper is the small rubber device that sits at the bottom of your toilet tank. The flapper is attached by a chain to a lift lever which leads to the handle on the front of your tank. Pressing down the handle lifts up the lever and flapper, which allows all the water inside the tank to rush out, carrying away the waste in the bowl. A slow toilet flapper can make your tank take longer to fill. Fortunately there are a number of different tricks you can try to make the toilet flapper close sooner.
Locate the water supply for your toilet with the slow flapper. This can usually be found on the wall behind the tank. Follow the supply line from the bottom of the tank to where it meets the supply valve in the wall. Rotate the valve clockwise to turn off the water.
Remove the tank lid. Flush the toilet. Hold down the handle as you do so to keep the flapper open and allow all the water to escape.
Place a brick into your toilet tank. You can add another if you have room. This will make your tank fill faster, decreasing the flapper hang time. It also has the benefit of using less water, which can lead to lower utility bills.
Increase the flapper chain length. Look at the end of the toilet lever, which connects to the back of the toilet handle on the inside of the toilet. You will see a chain leading down to the flapper. These chains can be adjusted manually. Unclip the top of the chain from the toilet lever and lengthen it by a few links.
Add a weight to the top of the flapper. Connect a small fishing weight to either one of the links above the flapper or the eyelet on the flapper. Additional weight will help make the toilet flapper close sooner.
Restore the water supply. Allow the tank to fill. Flush the toilet and check the flapper operation. Make any adjustments as necessary.