This backwash water passes into the clarifier tank in series and is then used for backwashing the clarifier. The backwash water from the filter passes through an eductor which can draw air. After a few minutes of backwashing with water only, the eductor valve is opened to allow air scouring of the clarifier bed. The air valve is closed to continue the upflow cycle and displace any accumulated air. The entire upflow cycles typically operates for 10 minutes.
Water passes through the clarifier and through the filter in series.
When the water is of acceptable quality, the unit is returned to service. The rinse cycle can vary from 2 - 20 minutes but is typically about 5 minutes. The entire cycle takes 15 - 20 minutes.