Systems and methods of controlling the speed of a pump configured to move liquid through a pump system are described. The actual motor speed of the pump motor is controlled by adjusting a current applied to the motor based on the difference between the actual motor speed and the target motor speed according to a gain setting. A first gain value is applied as the gain setting when the difference between the actual motor speed and the target motor speed does not exceed a first threshold. However, a second, higher gain value is applied when the difference between the actual motor speed and the target motor speed exceeds the first threshold.