With the continued increase in food prices and concerns about peak oil and climate change, many people are turning to their own backyards to grow some of their own food. However, not all of us our blessed with great soil and there are concerns about keeping water use to a minimum.
One method that addresses these issues and is proving to be a successful venture both commercially and for individuals and families is Aquaponics. Aquaponics is the most water efficient method of growing plants and fish together and uses a combination of aquaculture and hydroponics techniques.
Large amounts of vegies, herbs and fresh fish can be farmed from a backyard set up – even a small balcony can be converted into a rich food producing zone that the whole family can enjoy. Basically, an aquaponics system is made up of a tank containing the fish of choice and a series of grow beds filled with gravel for vegetable production.
Aquaponics uses nutrient-rich water from the fish tanks to circulate through the grow beds where plants are grown. Nitrifying bacteria that live in the grow beds convert fish wastes into plant-available nutrients.
The plants then use these nutrients and the clean water is returned to the fish in a continuous cycle.
Aquaponics uses no chemicals, requires one tenth of the water needed for field plant production and only a fraction of the water that is used for aquaculture (fish culture). Aquaponics systems are great for growing a wide range of vegetables including tomato’s, cucumbers, lettuce, spinach, strawberries, and other green leafy vegetables.
When aquaculture and hydroponics are used alone, there are a range of waste management issues that have to be dealt with. Water used in an aquaculture system quickly becomes too toxic for fish and must be disposed of – often into our waterways, which can cause further environmental problems.
This practice means aquaculture also uses a large amount of water as systems must constantly be emptied and refilled. Hydroponics on the other hand, requires the constant addition of nutrients and chemicals to the system to maintain plant growth.
When these too systems are combined to form an aquaponics system the negative aspects are cancelled out. The water is basically recycled with only a small amount of water added weekly to compensate for what is lost by evaporation and transpiration by the vegetables.
Therefore Aquaponics uses only about 10% of the water required for traditional gardening or fish farming. The Mt Pleasant Natural Resource Centre is hosting a workshop and field trip on aquaponics with Stuart Haberfield – an experienced DIY backyard aquaponics user, and small scale commercial aquaponics system operator.
This is a great opportunity to find out how Aquaponics works, learn about system design and operation – from small to large systems, the different fish species that can be farmed, costs of running the systems, general maintenance and get all your questions answered with Stuart.
Stuart presented a similar aquaponics workshop last year, but has been busily experimenting on his own systems and has much new information to share. The workshop is on the evening of Monday 15th September at Mt Pleasant, and the field trip is on Saturday 11th October.
For bookings or more information contact Faye by phone: 8568 1907 or email: firstname.lastname@example.org, alternatively check out our website on www.mpnrc.org.au
A backyard aquaponics system showing a newly re-planted grow bed (photo by Joel Malcolm,