Disclosed herein is a method of automatically calibrating a liquid treatment system in a seed treater. The method is performed by pumping a seed treatment liquid using a seed treater pump, receiving the seed treatment liquid in a container, detecting when a predetermined volume of seed treatment liquid has filled the container using a first level sensor and a second level sensor and automatically adjusting a flow rate of the liquid in response to a time required to fill the container. Adjusting the flow rate may be done by adjusting a speed of the pump.