IBC water tank guide: rainwater, irrigation and wicking beds

Ask what the container held and how the seller knows. An empty look, a clean smell or a missing label does not mean there is no residue. Previous contents can affect the plastic, seals and valve.

If the history is unknown, washing will not make it safe. Choose a container known to suit the use, especially where the water will reach people, animals or food crops.

Even a suitable tank does not make rainwater clean. Roof debris, animals, roofing materials and still water all affect quality. The system needs regular upkeep.

Victoria's Department of Health rainwater guidance explains rainwater quality and maintenance. Business and community systems may need more care than a small backyard setup.

Label non-drinking water taps clearly. Never connect a tank to mains water or indoor plumbing without a licensed plumber. Plan where overflow will go before connecting a downpipe, so it does not cause erosion, flooding or wash out the ground under the tank.

A common 1000 litre unit is about 1200 by 1000 by 1160 mm, but models differ. See the dimensions guide for manufacturer examples.

Leave space to reach the valve, the filling cap and the base. A tank pushed hard against a fence is hard to check. A valve hidden behind stored gear cannot be shut off quickly.

A full 1000 litre tank weighs about one tonne plus the container. The ground and base must carry that load evenly. Do not sit it on loose blocks or a shaky stand. If you want it raised for extra pressure, get a structural check first.

Never move a full tank with equipment chosen for its empty weight.

IBC valves vary. The valve size alone does not tell you the thread or seal. Photograph the valve and ask the fitting supplier to match it. Do not force an adaptor that nearly fits.

Support pipes so they do not pull on the valve. A heavy hose hanging off an old fitting can cause a leak even when the tank is fine.

An IBC water tank pump should suit the use and be wired by a licensed electrician. Do not run makeshift wiring near water.

If you rely on gravity, check the pressure your irrigation needs. A tank at ground level may not run equipment designed for mains pressure.

Sunlight can age plastic and affect stored water. Do not assume a used unit has UV protection because some new models do.

A cover cuts light, but it does not change what the tank held or repair old plastic. Make sure the cover does not hide leaks. If you add cladding, leave access to the inlet, valve and overflow. Do not hang loads off a used cage.

A wicking bed has a water reservoir under the soil that feeds plants from below. That does not make an unknown industrial IBC a safe growing container. What it held still decides the question.

For food crops, use a container known to suit that use. Paint, a rinse or a loose liner will not fix uncertain contamination.

Cutting an IBC weakens it and leaves sharp edges. This guide does not give cutting instructions. If you clad an IBC wicking bed, keep the reservoir, overflow and inspection points easy to reach.

Cleaning is the buyer's job, and the method must suit what the tank held. Do not mix cleaning chemicals or use solvents without guidance. Never climb inside a container.

Minor residue may remain in a used as-is unit. If the residue is unknown or could be hazardous, stop and get specialist advice. Never pour residue or washwater into stormwater, soil or a drain. A clean-looking tank is still not proof it suits a sensitive use.

A bund catches liquid if the tank leaks. Whether you need one depends on the liquid, the amount, the location and what a spill would damage.

EPA Victoria's liquid storage and handling guidance explains how to manage spill risk. Do not apply one rule to every site and liquid.

For water only, think about flooding and drainage. A bunded pallet does not make a used unit suitable for chemicals or dangerous goods. Keep the bund clear of rainwater and debris so it still works.

• Write down the use, the volume you need and any site limits.
• Ask for the history, condition photos, measurements, base type and valve details.
• Confirm the base, plumbing, overflow and access before it arrives.
• Use a licensed plumber or electrician where needed.
• Check the tank regularly. If it leaks, changes shape or looks worn, stop using it.