Abstract: The float valve (11) controls water level e.g. in an associated plant pot. A housing (21) has a water inlet (25) with an inlet port (26), a float (31) able to rise and fall with the level of the water in the housing (21), a valve operating mechanism (60) able to open and close the port (26), and an actuator means (40) to operate the valve operating mechanism when the float (31) rises and falls to predetermined levels. For opening and closing the inlet port (26), there is a valve operating mechanism comprising a valve operator (60) having a valve member (67) and a lever (61) mounted for pivoting movement about generally central pivot point (65). Actuator means (40) is coupled to the float (31) and switches between a standby condition an active condition respectively to the closed and open positions of the valve operating mechanism (60).