An aquaponics garden in Melbourne
Our March meeting was held at Robbie’s home in the inner northern suburbs of Melbourne and he gave us a tour of his aquaponic gardens.Aquaponics is combining of aquaculture & hydroponics. This means that fish and plants are grown in an integrated system, creating a symbiotic relationship between the two.
Robbie explained that at the heart of the system is 1000L water tanks populated with up to 100 fish each, these fish excrete wastes which through biological activity turns into ammonia then nitrates which is then available as a natural plant fertiliser. This food production process is very sustainable since no fertiliser or pesticides need be added to the garden. The fish are feed twice daily with granular fish food and he explained for really keen gardeners, a more sustainable option is available. Black Soldier flies can be harvested from a compost heap with the help of a special device attached which allows the fly larvae to crawl inside and collected ready for feeding to the fish. An extra form of nutrition can be provided by feeding them home grown duckweed.
Different species of fish have been grown with varying degrees of success, originally he purchased Silver Perch from Queensland and although they were meant to be suitable for our southern climate they couldn’t survive the cold Melbourne nights. He is currently growing rainbow trout and yabbies available from local fish farms. Robbie did warn that the availability of fingerlings (young fish)was very seasonal and if you didn’t buy them at the right time you might miss out until next year.
The whole garden was devoted to food production with fish, chickens and a large variety of edible plants grown in every corner. The morning was concluded with a morning tea and lots of questions for our host Robbie.