Toto has been a leader in the design of water-saving, highly efficient toilets. In addition to more stylized toilet shapes, Toto has streamlined the traditional flush mechanisms to improve water conservation, including simplified adjustments to tank's water level. The Toto flush valve comes in two versions, depending on the Toto toilet model, but the easy adjustment to set the effective the water level is the same for either valve type.
Shut off the water supply to the toilet. Turn the handle on the water valve mounted below and behind the toilet tank clockwise to close the valve.
Flush the toilet to drain the water from the tank.
Locate the flush valve within the toilet tank. The flush valve is a vertical tube in the center of the tank with a grooved grip at the top.
Turn the top of the flush valve assembly counterclockwise 1/2-turn to unlock the adjustment tube.
Adjust the valve tube to change the water level. Raise the water level by lifting upward on the flush valve tube to raise the "water line" mark on the outer surface of the tube, then twist the tube clockwise until it clicks to lock it at the new level. Lower the water level by pushing downward on the flush valve to lower the "water line" mark, then twist the tube clockwise to lock it.
Turn the water supply to the toilet back on to refill the tank. Flush the toilet to verify the adjusted water level setting is correct and effective.