Abstract: A flush water conserver adapted for easy retrofitting to existing standard toilet flush tanks is disclosed. The standard trip lever fixed to the pivot shaft of the toilet operating handle is replaced with a trip lever mounted on a pivot which is located between the operating handle pivot shaft and the adjacent sidewall of the flush tank. A rocker is affixed to the operating handle pivot shaft. This rocker is located below the new trip lever and the new trip lever rests on it. Thus, the new trip lever is raised when the operating handle is rocked in either direction. A control float is provided, and a stop is affixed to the flush ball stem. The stop is so constructed and located that when, during a flushing operation, the water in the flush tank has only partially receded, the weight of the control float is brought to bear on the stop, and thus the flush ball is pressed toward its seat while the control float continues to drop with the receding water.