The growth kinetics of a potassium sulfate crystal was investigated in the presence of traces of chromium(III) impurity (0.5 and 2 ppm) in a flow cell at different rates of change of supercooling (+/-0.1 and +/-0.2 degreesC/min). Hysteresis in crystal growth rates with chromium(III) impurity was induced by decreasing and increasing the supercooling. The rate of supercooling change affected this hysteresis behavior. The cause of hysteresis was hypothesized to occur due to a slow adsorption of impurity at high supercooling.