I'm currently staying in Broome with my brother for a few weeks so I thought I might share one of his creations. This aquaponics system consists of two 1000 ltr IBC's (Intermediate Bulk Containers) which are typically used for the transport and storage of fluids. One IBC is cut in two creating the main grow bed and sump while the other is home to ten barramundi.
IBC's are a popular choice as you can pick them up cheaply and they're ideal for the purpose provided they weren't carting toxic liquids in their past life. This setup pumps water from the sump into each of the grow beds and gravity feeds back into the sump. The main bed uses a flood and drain configuration to grow larger plants like tomatoes, egg plant and peppers with 20mm grade blue metal as the growing medium.
The smaller bed is a half barrel with a finer grade medium and drip system for herbs and smaller plants. The barra feed on whatever bait fish is available since they're destined for the dinner plate. Purely pellet fed fish don't have as nice a taste. Upgrading this rig is as simple as adding a new grow bed and piping it back into the sump. It's less than a year old and has performed well so far. Should only improve with more time to establish.