Liquid Fertiliser Storage Tanks: How to Get Set Up Before Spring Application

If you’re planning to store liquid fertiliser on your property, you need a tank built for the job: one rated for liquids heavier than water, made from a material that won’t corrode, and set up with the right bunding and placement. An ordinary rainwater tank won’t cut it — and using one can end in a split tank and a very expensive puddle.

With spring application only weeks away, right now is when smart growers lock in their storage. Bulk liquid fertiliser is cheaper than bagged product, but only if you’ve got somewhere safe to put it. So let’s run through what makes fertiliser storage different, how to size a tank for your spray program, and what to sort out before the delivery truck arrives.

Liquid fertilisers like UAN have become a staple across Australian broadacre and horticulture operations, and for good reason. They spread evenly, blend with other inputs, and go on fast through a boom spray. Buying in bulk adds another layer of value: per-litre pricing drops significantly, and you’re not waiting on a resupply run when the weather window opens.

The trade-off is that bulk product needs proper on-farm storage. That’s where purpose-built liquid fertiliser storage tanks come in — and where a few important differences from standard water tanks catch people out.

Here’s the number that matters: specific gravity, or SG. Water has an SG of 1.0. Common liquid fertilisers are considerably denser — UAN solutions, for example, sit around 1.3. In other words, every litre weighs roughly a third more than a litre of water.

A standard rainwater tank is engineered for the wall loads of water. Fill it with a denser liquid, and you’re asking the walls to hold weight they were never designed for. Over time, that leads to bulging, stress cracking, and eventually failure. Consequently, any tank storing fertiliser must carry an SG rating that matches or exceeds the product going into it.

The second issue is corrosion. Many liquid fertilisers are aggressively corrosive to mild steel, brass and copper. That rules out steel tanks and standard brass fittings for most fertiliser applications, and it’s why the industry has moved so firmly toward polyethylene.

Polyethylene doesn’t rust and doesn’t react with common liquid fertilisers, which makes it the natural fit for liquid fertiliser storage tank. A quality industrial poly tank gives you:

• Chemical compatibility with UAN and most common liquid fertiliser products
• Heavier wall construction engineered for higher-SG liquids
• UV-stabilised material built for years of Australian sun in an open paddock
• One-piece moulded construction — no seams or joins to weep under load

At The Water Tank Factory, our industrial storage range is manufactured by Duraplas Industries and BSI-certified to AS/NZS 4766, the Australian standard for polyethylene storage tanks. It’s the same heavy shot-weight approach we bring to every tank we’ve made since 1984 — thicker walls, more rigidity, longer life. You can browse the full range on our diesel, AdBlue & chemical storage tanks page.

One important note: always confirm the tank’s rating against the specific product you’re storing. Fertiliser blends vary, so tell us what you’re putting in the tank when you order and we’ll match you to the right model. Call the team on 1300 826 532.

How big should you go? Start with your program, not the tank catalogue. A rough method:

1. Work out your seasonal usage.
Application rate per hectare × treated area = total litres per season.

2. Decide how many deliveries you want.
One big fill before the season, or top-ups as you go? Fewer deliveries usually means better pricing and less freight.

3. Add a buffer.
A tank that holds 10–20% more than your planned volume gives you room for a price-dip purchase or a program change. For example, an operation applying 80 litres per hectare across 250 hectares needs 20,000 litres per season. A single tank in the low-to-mid 20,000-litre range covers that in one delivery, with change to spare. Smaller horticulture operations might land closer to 5,000 litres. In short, the maths is simple — the discipline is doing it before you buy.

Liquid fertiliser is a farm input, but a spill is still a pollution event. Before your tank arrives, think through:

• A level, stable base — remember, a full fertiliser tank is a third heavier than the same tank full of water
• Distance from waterways, drains and bores — your state EPA publishes guidance on chemical storage setbacks, and it’s worth checking before you pick the site
• Bunding or secondary containment where required — self-bunded options like SmartBund take the guesswork out for smaller chemical volumes
• Vehicle access for the delivery tanker and your spray rig, in all weather

Storage compliance is a topic of its own, and our guide to diesel and chemical storage compliance covers the wider rules in detail. If you’re weighing up poly options across several chemicals, the poly chemical tanks buying guide is the natural next read.

Here’s the timing part nobody enjoys learning the hard way. Spring is peak season for tank orders, fertiliser deliveries and freight companies alike. Order your storage in late winter, and everything lands before your program starts. Leave it until the crop is asking for nitrogen, and you’re at the back of everyone’s queue.

Because we manufacture in Australia and sell factory-direct, we provide a committed delivery date at the time of ordering — so you can plan your fertiliser delivery with confidence rather than crossed fingers.

No. Standard rainwater tanks are engineered for water, which has a specific gravity of 1.0. Most liquid fertilisers are around 30% denser, which overloads the tank walls and leads to cracking or failure. Always use a tank with an SG rating that covers the product you’re storing.

Multiply your application rate per hectare by your treated area to get seasonal litres, then add a 10–20% buffer. Many broadacre operations land between 10,000 and 30,000 litres, while horticulture blocks often suit 2,000–5,000 litres. The team at The Water Tank Factory can help you match a model to your program — call 1300 826 532.

Polyethylene is compatible with UAN and most common liquid fertilisers, which is why poly dominates on-farm fertiliser storage. The key is buying a tank rated for the product’s density and confirming compatibility for unusual blends. Steel tanks and brass fittings, by contrast, corrode quickly with many fertilisers.

It depends on the product, volume and your state’s rules. Some situations call for bunded or self-bunded storage, and siting rules around waterways apply everywhere. Check your state EPA guidance, and see our diesel, AdBlue & chemical storage tanks range for self-bunded options.

Late winter. Manufacturing and freight queues build quickly as spring approaches, and you want the tank sited and plumbed before your bulk fertiliser delivery arrives. Ordering factory-direct with a committed delivery date makes the timing easy to plan.

Bulk liquid fertiliser only pays off when the storage side is handled — the right SG rating, the right material, the right spot in the paddock. Sort it now, and spring becomes a matter of opening the valve.

The Water Tank Factory is the online sales division of Duraplas Industries — Australian family-owned, manufacturing since 1984 in Alstonville, Northern Rivers NSW, with over 250,000 tanks manufactured. Explore the industrial storage range at www.watertankfactory.com.au or talk to the team on 1300 826 532 about the right tank for your program.