The gear I use | Frugal Energy

Most of what follows is the frugal DIY route: eBay, AliExpress and salvaged bits. Murray Hallam also sells aquaponics gear at Aquaponics.net.au if you would rather buy purpose-built kit. Worth a look, especially after you have done his course.

Power: keep it DC

Everything below runs off my solar and battery setup. I keep it all DC at 24V where I can, with no inverter in the path. Panels, MPPT chargers, batteries, wiring and the stay-below-50V rule are covered properly in the renewable energy section.

Main water pump

My main pump is a SunSun XDP6000 24V DC adjustable-flow pump. I went DC so it runs straight off my battery and solar with no inverter in the way, and it sips power. The adjustable flow is the handy part, because you can dial the rate up or down with the controller to tune the system without changing any plumbing.

One honest note: the headline flow rate on any pump is the figure at zero lift. The higher you push water up to a raised bed, the less flow you actually get, so size up rather than down.

SunSun XDP6000 kit: 24V DC pump, variable-speed controller, and hose fittings. Dial the flow without touching the plumbing.

Aeration (air pump)

Aeration matters as much as the water pump, because the fish and the beneficial bacteria both need oxygen to do their job. I run a 24V DC aquarium air pump feeding airstones in the fish tank and the sump. Going DC means it runs straight off my battery and solar like everything else, with no mains and no inverter.

Aquarium Air Pump Fish Tank Aerator Strong Flow DC 12V or 24V (24V version), eBay seller playhouse2022.

Disk airstones in a few sizes from AliExpress. Cheap, and they spread fine bubbles across the fish tank and sump.

The backup pump (the failsafe)

The single worst thing that can happen is your main pump failing while you're out, because without water movement the fish run out of oxygen fast. So I built a simple, cheap failsafe.

I use a 12V/24V bilge pump paired with a float switch. The float switch sits in the sump and watches the water level. If the main pump stops doing its job, the level changes, the float switch trips, and the bilge pump kicks in to keep water moving around the fish tank and sump. It is not running the whole system, just doing the one job that matters: keeping the fish breathing until I sort the main pump out.

The float switch in my sump: when the level drops, it trips the backup bilge pump.

A bilge pump is built for boats, so it is cheap, rugged and made for exactly this kind of intermittent emergency duty. And because it is DC, the failsafe keeps working even in a blackout.

The backup bilge pump: cheap, rugged, and built for intermittent emergency duty.

Worth being honest with readers: a bilge pump is for intermittent emergency duty, not continuous running. It is there to buy you time, not to run the system long term.

For the wiring join on the backup pump, I use a waterproof inline junction box from AliExpress. Strip the cable, click the wires into the lever terminals inside, screw the two halves together, and tighten the gland nuts at each end. Keeps the join dry when it is sitting out in the weather.

Waterproof inline junction boxes: lever terminals inside, sealed cable glands at each end. I run one on the backup pump connection.

Protecting your electronics outdoors

The system lives outside, so anything electrical has to cope with rain, sun and damp. This is the part of my background I lean on most, and the fix is cheap.

I house the controller and connections in IP67-rated waterproof enclosures. IP67 means properly sealed against dust and water, which is what you want for anything sitting out in a Gold Coast summer. I use SparkNova transparent enclosures and DAHO hinged ABS enclosures.

Clear-lid waterproof enclosures from AliExpress: pick a size that fits your controller and connectors, screw the lid down, and keep the rain out.

Hinged latch enclosures from AliExpress: open on a hinge, clip shut, and mount your gear on the perforated back plate.

For the wiring itself I use lever-type push-in connectors (the Wago-style blocks). These fast wiring connectors from AliExpress do the same job: flip the lever, insert the wire, and you have a tidy connection you can undo and redo when you are tweaking the setup, which beats twisting wires and taping them up. Keep the joins inside the enclosure and your low-voltage wiring stays safe and dry.

Fast wiring connectors with lever terminals: tool-free joins you can reopen when the setup changes.

I also highly recommend conductive lubricating grease on any wired connection that lives outside. A thin smear on terminals and screw joins keeps corrosion down and contact resistance low in the heat and damp. I pick it up from AliExpress; the tubs are cheap and last ages.

Conductive lubricating grease: a thin smear on outdoor terminals helps keep corrosion out and contacts reliable.

A reminder: water and electricity are a bad mix. Running low-voltage DC helps a lot, but follow your local rules for anything mains, and if in doubt get a sparky.

Handy bits: the fish net

A small thing that earns its place: a fine-mesh aquarium net for moving fish, harvesting, and scooping the odd leaf or bit of debris off the water surface. Cheap, and you will use it constantly.