Fluidmaster's Adjust-A-Flush toilet flapper valve adjusts the volume of water that flows from the tank into the bowl for each flush. A dial setting on the flapper adjusts the amount of air escaping from the cone of the flapper, altering how long the valve floats in the open position before "flapping" shut. This saves water and is a more efficient way of controlling flush volume than lowering the water level in the tank itself. The Adjust-A-Flush is no more difficult to install than a standard flapper and does not require any special tools.
Shut off the water supply to the toilet tank. Flush the toilet to drain the tank.
Remove the old flapper and chain. Use a rag to clean the drain seat of the valve.
Snap the adapter ring off the Adjust-A-Flush flapper. Slide the flapper assembly down over the overflow drain pipe, centering the flapper over the drain opening. Lock the flapper assembly to the mounting ears on the overflow pipe by pushing down firmly. Make sure the flapper opens and closes freely.
Connect the flapper chain to one of the holes in the tank handle arm. Select a hole that will allow only slight slack in the chain when the flapper is closed.
Turn on the water supply and check for proper seating of the flapper. Make sure the chain length is correct and not too tight to prevent the valve from closing completely, or so loose that the slack chain may get caught in the valve opening.
Adjust flush volume by rotating the flapper around numbered settings printed on the body of the valve. The chain attachment fitting on the valve frame is the center point. Rotate the flapper body from "1" for the quickest flush/lowest water volume to "9" for the longest flush/maximum water volume, with "4" as the standard setting.