Catfish is a freshwater fish commodity which is easy to cultivate but has cannibalistic nature. There are 3 phases of catfish cultivation: fingerling, rearing, and fattening. The fattening phase is a stage of nursery to produce catfish according its size to be consumed. During this stage, it’s vital to regularly feed the fish at morning (7 am), noon (1 pm), and evening (5 pm) and monitor water quality so catfish farmers are helped. This tool implements Arduino Mega, ESP-8266, 20 WP solar panel, 755 80W DC motor, servo motor, ultrasonic sensor, fish food container, and DS3231 RTC. This research has 3 scenarios: scenario 1: food given sparingly twice/day, scenario 2: the IoT fish feeder automatically supply food thrice/day at morning (7 am), noon (1 pm), and evening (5 pm). scenario 3: food provided extravagantly twice/day. This research resulted an autonomous IoT fish feeder It is proven that scenario 2 has satisfactory results, fish growth is better 33.3% when compared to scenario 1 and is relatively the same as fish growth in scenario 3. Meanwhile, the amount of food spent is 25% from scenario 3. The level of turbidity is also better at 37.5% compared to scenario 3.