Abstract: A water level control for swimming pools is provided in the form of a casing for suspension on a ladder, pool wall, or pool edge having a float-controlled valve detachably coupled with a pressure water supply and adapted to open as the float drops a predetermined distance within the range of about 3/4 inch to 1 inch, said casing having a transverse partition intermediate its upper and lower ends which supports the valve and float assemblage, and said partition and casing bottom being apertured to permit egress of water fed through the valve while in open position while at the same time acting as baffles to maintain an essentially stable water level within the casing in spite of the wave action which may prevail in the surface of the pool water. Positioning of the casing is facilitated by external high and low water level markings which align with the water levels within the casing at the upper and lower limits of float movement.