Abstract: A flow control nozzle for directing a liquid through the floor of a liquid containing basin which includes: a substantially vertical tubular portion having a lower end adapted to extend through the floor of the basin; a chamber portion having a bottom surface adapted to communicate with an upper end of the tubular portion, the bottom surface having openings formed therethrough and being positioned a predetermined distance above the floor of said basin so as to permit liquid to pass therethrough into said chamber portion; and an air vent tube having an upper end adapted to communicate with the atmosphere and a lower end adapted to communicate with said tubular portion.