  Aquaponics system promises a sustainable urban development and food
production by combining vegetable and fish farming in a single water loop.
However, traditional aquaponics suffers from a significant amount of manual
intervention with regard to decision-making in the water circulation and water
quality control. In this work, we design, build and deploy a laboratory-scale
real aquaponics system by considering this system as a cyber physical system,
and we call it as Cyber Physical Aquaponics (CyPhA) system. The design of our
CyPhA system has five stages, Stage-1 contains a vertical vegetable farming
unit, Stage-2 contains fish farming unit, Stage-3 contains natural
nitrification system, Stage-4 contains bio-filtration system and Stage-5
contains water accumulation and release system. Water transfer from one stage
to the next is done using water pumps, and oxygen mixing in the water in any
stage is achieved using aeration pumps. CyPhA system uses sensors for pH,
dissolved oxygen (DO), total dissolved solid (TDS), water temperature, air
temperature and humidity. A critical level of any of the water parameters in
any stage is indicated using a LED-based alert indicator. Sensor data and
actuator control commands among the stagewise edge devices and the CyPhA
Controller are exchanged over Message Queue Telemetry Transport (MQTT)
protocol. Overall, CyPhA system is housed within an area of about 80 sq. ft. We
have been successfully operating CyPhA system for the last 75 days and
maintaining a good quality of water for both fish and vegetable farming units.
