A limitation of our method lies in occasional disturbance when the mesh collector was moved. After the uneaten feed was captured, the collector was removed by hand. Although this was done carefully, some fish were startled by the hand entering the water. However, the operation was completed in a few seconds.The fish quickly resumed normal swimming and feeding behavior.The stress did not seem to affect growth, as the body weight gain showed. A system using hooks to remove and replace the collector could be designed for use if fish are excessively disturbed or in a tank too deep to allow removal by hand.