THE SMART FOLK over at Perth City Farm have found a way to enjoy some tasty fish with the vegetables they grow. This they do through an aquaponic system — an integrated vegetable/fish production unit that yields Australian freshwater fish.
The system circulates water — and the nutrients it picks up — through a series of raised vegetable beds and, finally, into a fish tank. The water and nutrients are then recirculated back through the vegetable beds. The plants and fish benefit from the circulated nutrients, although the fish may need some supplementary feed.
Perth City Farm's system consists of three round, galvanised iron beds and a deeper galvanised iron tank for the fish. The beds are filled with an organic growing medium. The city farmers have installed interpretive signage so that visitors understand what goes on in the system.
Aquaponic systems offer a source of urban protein. They may require a little tweaking to get them working efficiently, and the right species of freshwater fish must be chosen for the climate.
DIFFICULTY: High. Needs technical knowledge of construction, pisciculture (small scale fish farming) and control of water.
EFFECTIVENESS: Effective is properly managed. Potential as a source of urban protein and vegetables in small spaces. Commercial potential to supply fresh food markets.
SCALABILITY: Good. Can be scaled up in size and replicated based on successful models.
REPLICABILITY: Good potential. Requires knowledge/advice on design and management of the technology.
Commercial versions of the technology are available on the market for home or community garden deployment.
Materials: Low. Electric pump will require skilled maintenance.
Skills: High — manual skills for construction; electrical skills/electrician to wire up pump; basic horticultural and fish management skills to operate biological component of the technology.
Story: Russ Grayson