How to Choose the Right Water Tank | Complete Water Tank Buying Guide
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Not sure which water tank to buy? Learn how to choose the right size, shape, material and installation location for your home, farm or business with our comprehensive buyer’s guide.
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How to Choose the Right Water Tank: A Complete Buyer’s Guide
Whether you’re preparing for municipal water interruptions, collecting rainwater or storing water for agricultural use, choosing the right water tank is one of the most important decisions you’ll make.
A tank that is too small may leave you without enough water during periods of high demand. A tank that is too large may take up unnecessary space and increase your initial investment.
The right tank balances your available space, daily water requirements, budget and intended application.
This guide explains the key factors to consider before purchasing a water storage tank, helping you select a solution that will provide reliable service for many years.
Why Choosing the Right Tank Matters
A well-chosen water tank provides:
- Reliable backup water.
- Better drought resilience.
- Reduced dependence on municipal supplies.
- Lower long-term operating costs.
- Greater flexibility for future expansion.
- Improved rainwater harvesting capacity.
Choosing carefully now can prevent expensive upgrades or replacements later.
Step 1: Decide What the Water Will Be Used For
The first question to ask is:
What will the stored water be used for?
Common applications include:
Household Backup Water
Used during municipal supply interruptions for toilets, washing, showers and general household use.
Drinking Water
If the stored water will be used for drinking, food preparation or cooking, ensure both the tank and any treatment system are suitable for potable water.
Rainwater Harvesting
Ideal for collecting roof runoff to reduce reliance on municipal water.
Garden Irrigation
Water tanks provide an efficient source for watering lawns, vegetable gardens and landscaping.
Agricultural Use
Common applications include livestock watering, crop irrigation and equipment washing.
Commercial and Industrial Storage
Businesses often use tanks to maintain operations during supply interruptions or for process water.
Step 2: Estimate Your Water Requirements
Choosing the correct capacity is essential.
Start by estimating your average daily water usage.
Typical residential consumption varies depending on household size, lifestyle and water-saving practices.
For example:
| Household Size | Approximate Daily Water Use* |
|---|---|
| 1–2 people | 150–350 litres |
| 3–4 people | 400–700 litres |
| 5–6 people | 700–1,000 litres |
| Larger households | 1,000+ litres |
*Actual usage depends on local conditions and individual habits.
Also consider how many days of backup water you would like to store.
Step 3: Choose the Right Tank Size
Water tanks are available in many capacities.
General recommendations:
| Tank Capacity | Suitable For |
|---|---|
| 500–1,000 litres | Garden use, small backup supply |
| 2,000 litres | Small homes or cottages |
| 3,000–5,000 litres | Average family home |
| 10,000 litres | Larger homes or small farms |
| 20,000 litres and above | Farms, businesses, commercial applications |
Remember that multiple tanks can be connected together if your storage needs grow over time.
Step 4: Select the Best Tank Shape
The available space on your property often determines the most suitable tank design.
Vertical Water Tanks
Best for:
- Large storage capacity.
- Smaller ground footprint.
- Residential properties.
- Farms.
- Commercial sites.
Slimline Water Tanks
Best for:
- Narrow side passages.
- Boundary walls.
- Limited outdoor space.
- Urban properties.
Horizontal Water Tanks
Best for:
- Mobile water transport.
- Low-height installations.
- Water bowsers.
- Agricultural trailers.
Underground Water Tanks
Best for:
- Preserving outdoor space.
- Large rainwater harvesting systems.
- New building projects.
- Commercial developments.
Step 5: Consider the Installation Location
Before purchasing a tank, check:
- Available space.
- Vehicle access for delivery.
- Access for future maintenance.
- Ground stability.
- Nearby downpipes or plumbing connections.
- Sun exposure.
Planning the location carefully simplifies installation and ongoing maintenance.
Step 6: Build a Proper Base
A water tank should always rest on a stable, level foundation.
Suitable bases include:
- Reinforced concrete slabs.
- Properly compacted crusher dust.
- Engineered gravel foundations.
Avoid placing a tank directly on uneven soil, bricks or loose materials.
A poor foundation can lead to uneven loading and shorten the tank’s lifespan.
Step 7: Choose the Right Accessories
A complete water storage system often includes:
- Leaf strainers.
- First-flush diverters.
- Tank connectors.
- Overflow fittings.
- Ball valves.
- Float valves.
- Tank level indicators.
- Pressure pumps.
- Filtration systems.
- Pressure controllers.
Selecting compatible accessories improves system reliability and convenience.
Step 8: Think About Future Expansion
Your water needs may increase over time.
You may later wish to:
- Add more storage capacity.
- Install a booster pump.
- Connect additional tanks.
- Upgrade to a rainwater harvesting system.
- Supply more buildings.
Planning for future expansion can reduce installation costs later.
Common Mistakes to Avoid
Many water tank problems begin with poor planning.
Avoid these common mistakes:
- Buying the cheapest tank without considering quality.
- Choosing a tank that is too small.
- Ignoring available installation space.
- Failing to prepare a proper base.
- Forgetting overflow management.
- Not allowing room for maintenance.
- Overlooking future water needs.
Frequently Asked Questions
Is one large tank better than several smaller tanks?
Both options have advantages. Multiple interconnected tanks provide flexibility and redundancy, while a single large tank may require fewer fittings and simplify installation.
Can I install a water tank myself?
Smaller domestic tanks can often be installed by competent homeowners. Larger tanks and more complex systems may require professional installation to ensure correct foundations, plumbing and compliance with local requirements.
How long do water tanks last?
High-quality UV-stabilised polyethylene tanks can provide many years of service when installed correctly and maintained according to the manufacturer’s recommendations.
Can I connect a pump directly to my water tank?
Yes. Many systems use a pressure pump to deliver water from the tank to household plumbing or irrigation systems. The pump should be selected according to the required flow rate and pressure.
Conclusion
Choosing the right water tank is about more than simply selecting a capacity. By considering your water usage, available space, intended application and future needs, you can invest in a storage solution that delivers reliable performance for years to come.
Whether you’re installing a small backup tank for your home or designing a large agricultural storage system, careful planning and quality components will help you make the most of your investment.
Related Articles
Continue learning in our Water Storage Knowledge Centre:
- The Complete Guide to Water Storage Tanks
- Water Tank Installation Guide
- How to Calculate Water Tank Size
- Slimline vs Vertical Water Tanks
- Above-Ground vs Underground Water Tanks
- Rainwater Harvesting Explained
- Water Tank Maintenance Guide
- How to Clean a Water Storage Tank
- Water Tank Accessories Explained
- Choosing the Right Water Pump for Your Tank