Backyard Aquaponics
A place to discuss aquaponics

AQUAPONICS at Baw Baw Community Gardens
By Jay Birchall

• Aquaponics is a combination of ‘Aquaculture’ and ‘Hydroponics’ where fish are used to fertilize plants.
• The rocks that we plant in create a ‘filter’ that accumulates specific bacteria that converts the ammonia, created by the fish’s excrement and breathing, into nitrogen for the plants to eat.
• The whole system is powered by electricity, fish food, and occasionally Seasol for micronutrients.
• You can plant most edible plants into AP (aquaponics) except for some root vegetables like potato, but I’ve had great success with onions and beetroots.
• Trout are used as a popular fish during the cooler months with a 5-6 month growout to plate size. Silver Perch are another popular species that grow to plate size over 2 years and survive the summer and winter months. Goldfish, Tandus catfish, Jade Perch, Bass, Barramundi are some other species used.
• Initially the system must ‘cycle’ to establish a bacteria colony that converts ammonia into nitrite and then nitrate. This can be done with or without fish, I prefer Charlie Carp, and takes about 2-6 weeks depending on the temperature. Ideally you can ‘seed’ your system from someone else’s AP water to get things going.
• It’s a great way to garden if you don’t like watering your garden all the time and “research has shown that an aquaponic system uses about 1/10th of the water used to grow vegetables in the ground.”
• I’ve found leafy greens are the most successful as they love the nitrogen.
• I’ve learnt all I need to know form online community forums and reading AP literature, particularly THEIBCOFAQUPONICS.PDF from backyard aquaponics website.
• It’s a great way to use recycled materials and get the ‘double harvest’ of veges and fish.

A basic system can be setup using an IBC tank which is then cut up into a 700 ltr fish tank and 300 ltr growbed. Cost for plumbing, pump, rocks, tank, fish, food would be about 250$. You can also use Blue barrels, bathtubs, wood framing and pond liner etc.