Aquaponics

Intro

The goal of this project was to create a system which allowed me to grow fresh vegetables in my small apartment. I selected an aquaponics design, which creates a symbiotic loop where the fish provide natural fertilizer for the plants, and the plants, in turn, filter and clean the water for the fish. This closed-loop ecosystem is not only highly space-efficient, but it also incredibly healthy for the fish and plants. To optimize this miniature ecosystem, I automated its core functions using an Arduino Uno to manage scheduled LED grow lighting and pump timing, ensuring consistent plant growth and tank health. The result is a blend of biology and technology, a compact, self-regulating garden that produces fresh vegetables right in my living space.

Frame

I constructed the frame from repurposed aluminum extrusion to create a rigid yet modular foundation for the fish tank, grow beds, lighting, and control electronics. For the grow bed, I designed a two-part model in FreeCAD, which I then 3D-printed, assembled with marine epoxy, and finished with a silicone sealant to ensure it was completely watertight.

Electronics

I controlled the entire system with an Arduino Uno and a custom circuit I built on a prototyping shield. The Arduino managed the timing of the water pump and grow lights using a DS3231 RTC module, and powered Bridgelux LED light strips via constant-current buck converters. I actuated a low-cost USB aquarium pump using a MOSFET, setting it on a timer to fill and drain the grow bed.

Future Plans

The current prototype has been working reliably for nearly a year, successfully providing me with fresh vegetables. However, I plan several upgrades to improve its performance and maintainability. Converting to an ESP32 microcontroller with WiFi capability would eliminate the need for a separate RTC module and enable remote configuration and monitoring. Additionally, moving from the breadboard shield to a custom PCB with integrated LED drivers would reduce points of failure and significantly clean up the wiring.