A method is provided for controlling the fluid level in an ebb and flow watering system control bucket that is in fluid communication with at least one fluid holding apparatus such as a plant container with connecting water lines, causing hydraulic delays in changes in the fluid level in the control bucket when fluid is pumped to or from the control bucket, typically from a fluid reservoir. The method involves pumping fluid to or from the control bucket to achieve a target fluid level in the control bucket; upon the fluid reaching the target fluid level, starting a timer for a short period of time to allow for the hydraulic delays, and continuing to pump fluid while the timer runs; restarting the timer and continuing to pump fluid if the fluid level in the control bucket recedes from the target fluid level; and discontinuing pumping if the timer runs for the full period of time.

In a ball tap 1, a valving element 3 includes a valve part 10 provided with a contact projection part 9 that can come into close contact with a valve seat 7 when the valving element 3 is closed, and a flange part 11 having a circular ring shape in plan view which continues downward from the rim of the valve part 10 and is slidable like a piston in the secondary side flow passage 5, and the left and right half circumferences of the upper surface of the flange part 11 have bilaterally symmetrical shapes curved downward in arch shapes, and the left and right lower limit portions of the upper surface of the flange part are set so as to be positioned at the same heights as those of the lower end edges of drainage ports 8.