An Autonomous Solar-Powered Smart Aquaponic System: IoT-Enabled Architecture and Comparative Growth Evaluation of Kale and Nile Tilapia

Aquaponics is an integrated food production system that combines aquaculture with hydroponics, using nutrient-rich fish wastewater to support plant growth through continuous recirculation. This study designed and evaluated a smart, solar-powered aquaponic system with Internet of Things (IoT) monitoring and control in a closed-loop configuration. The system comprised distributed sensors for temperature, humidity, pH, and water level; a microcontroller-based control unit; and automated actuators powered by a photovoltaic panel, charge controller, and battery. Over a 70-day trial under high ambient temperatures (41.06 ± 1.56 °C), kale (Brassica oleracea var. acephala) grown in the aquaponic system (n = 60) was compared with a conventional soil-based control (n = 60). No significant differences were detected in plant height (10.39 ± 3.00 vs. 9.78 ± 2.52 cm; p = 0.232), leaf width (4.70 ± 1.12 vs. 4.60 ± 1.05 cm; p = 0.615), or leaf number (7.88 ± 2.10 vs. 7.62 ± 2.16; p = 0.495). Nile tilapia (Oreochromis niloticus) in the same system achieved 100% survival (n = 10). These results indicate that the IoT-enabled system supported kale and tilapia production over the trial period.