Grow vegies, herbs and fish in your backyard with an environmentally friendly aquaponics system – a combination of aquaculture (fish farming) and hydroponics (growing plants in water). Put simply, water from a fish tank/pond is reticulated through to gravel-filled beds to feed plants. As the water contains fish waste, the plants lap it up like a liquid fertiliser, removing the nutrients before returning it to the tank or pond. It’s a thriving and renewable organic harvest system and also a beautiful living sculpture. Learn how a setup could benefit your backyard.
Gather your supplies
Large planter box with drainage (we used an old bathtub)
Fish tank (we used a custom-built tank)
40mm river pebbles (4 bags)
20mm river pebbles (an adequate quantity to form a 50mm layer)
The system set up depends on materials used and garden space. For best results, ask an aquaponics professional for advice.
- Step 1: Excavate ground for tank then position and ensure it’s level.
- Step 2: Determine position for planter box (it should be next to tank, close enough so outfall from planter box overflows to tank) then excavate to desired depth. Fill hole with concrete and ensure it’s level. Leave to set then position 2 concrete blocks on top.
- Step 3: Apply a generous amount of construction adhesive to top of each block then put another block on top. Repeat for last 2 blocks and allow to set.
- Step 4: Put planter box on blocks with outfall positioned over tank.
- Step 5: Fill tank with water and put pump with irrigation pipe in end furthest from planter box. Run pipe the length of tank and up and over lip of planter box.
- Step 6: Fit flanged seal and output to planter box before fitting the bell-syphon valve.
- Step 7: Add 40mm pebbles to planter box and spread evenly. Fill to within 50mm of rim.
- Step 8: To cover sides of planter box, cut end posts to fit then screw from top corners of planter box into posts to secure.
- Step 9: Cut side panels to fit and drill into end posts to secure. Top panel should sit flush with lip of planter box. Cut and fit top edging panels to sit over lip then drill to secure. Fill planter box to rim with 20mm pebbles.
- Step 10: Rinse soil from roots of plants then plant into pebbles. Turn pump on to start system.
- Step 11: Allow water in tank to settle for a few days then cut mesh to fit on top and release fish into it.
You’ll also need
Concrete blocks (6); concrete mix; construction adhesive; water pump; bell-syphon valve; 19mm irrigation pipe and fittings; flanges and pipes for waste output; mesh to cover tank; timber for framing and posts (we used timber from an old fence); selection of plants