How do I Adjust the Amount of Water Which is Used by my Toilet in the Half Flush Mode?
Because the half-flush float is the one which sets the half-flush level, the height of this float controls the volume of water released in a half-flush operation. The higher the half-flush float is positioned, the less water will be released through the seal into the toilet below. The lower the half-flush float is positioned, the greater volume of water will be released per half-flush cycle.
Dual-flush valves usually allow for adjustment of the height of the half-flush float. Check the manufacturer’s guide to determine how to adjust the half-flush float level. Some of them require a twist before they can be adjusted, others have a button on the side which releases the half-flush valve for positioning.