Introduction
When choosing a water storage tank for your irrigation system, the two most common options are galvanised steel and polyethylene (poly) tanks. Both have their place—but depending on your usage, one may suit your needs better than the other.
In this post, we’ll compare galvanised and poly tanks across five key areas so you can make an informed choice for your farm, nursery, greenhouse, or sports facility.
Durability & Longevity
Galvanised Steel Tanks
Made from corrugated steel sheets with a zinc coating
Extremely strong and resistant to impacts
Lifespan: 20–30 years (with proper liner maintenance)
Poly Water Tanks
Made from UV-stabilised plastic
Less prone to rust or corrosion, but can become brittle over time
Lifespan: 10–20 years
Winner: Galvanised—ideal for long-term, heavy-use environments
Size & Capacity
Galvanised Tanks
Modular and scalable—available in capacities up to 500,000+ litres
Ideal for large-scale farms, golf courses, and commercial nurseries
Poly Tanks
Typically range from 1,000–30,000 litres
Better suited for smaller greenhouses, garden centres, or residential use
Winner: Galvanised – if size matters, steel wins hands down
Installation & Flexibility
Galvanised Tanks
Require more prep: a flat concrete or compacted sand base is essential
Professional installation recommended
Can be disassembled and relocated
Poly Tanks
Lightweight and easy to position
Can often be installed without heavy machinery
Great for tight or awkward spaces
Winner: Poly – perfect for quick, DIY-friendly setups
Maintenance & Repairs
Galvanised Tanks
May need periodic liner replacement
Algae buildup can be an issue without a cover
More resistant to cracking or puncture
Poly Tanks
Minimal maintenance, but check for sun damage or stress cracks
Cannot be patched easily if large cracks form
Winner: Draw – poly is low maintenance, steel is more resilient
Cost Comparison
Galvanised Tanks
Higher initial investment
Better long-term value due to scalability and longevity
Poly Tanks
More affordable upfront
Ideal for budget-conscious or temporary setups
Winner: Depends – short-term = poly, long-term = galvanised
Cost Comparison
| Use Case | Best Option |
|---|---|
| Large farms or commercial irrigation | Galvanised Steel |
| Small greenhouses or nurseries | Polyethylene |
| Fire suppression or emergency storage | Galvanised Steel |
| Temporary setups or tight access areas | Polyethylene |
Let’s Help You Choose the Right Tank
At KG Irrigation Services, we supply and install both galvanised steel and poly water tanks—always matched to your needs, budget, and space.
We’ll talk you through:
– What size tank you actually need
– What material works best for your site
– How to install it with minimal downtime
➡️ Speak to our team today or view our Water Storage Services for more.
