What Sized Water Tank Do I need?
What size water tank do I need? Explore round, slimline, and fire water tanks. Steel tanks offer durability, savings, and essential bushfire protection
What sized water tank do I need”? Is a good question, because the answers vary depending on how much water you use! Obviously, the bigger your water tank is, the more water you can store in it. Some of the things you should keep in mind when decided how big your rainwater tank should be include
Jump to sections – this article will cover
Water Tank Size | Water Tank Dimensions | Reduce Your Water Bills | Buying A Water Tank
Water Tank Size
Water Tank Dimensions
Depending on the space available, and your personal preferences, you can choose whether to order a round or slimline water tank(s). Round water tanks are a common sight across Australia, particularly in regional areas, while slimline water tanks are popping up more and more in urban Aussie backyards and are loved for their space-saving, sleek design.
Slimline Water Tanks
Slimline Water Tanks are ideal for where you have limited space (under eaves, for example) making this water tank design particularly well-suited to urban areas with smaller backyards. They’re also widely considered a more aesthetic choice.
However, there is a caveat: the maximum water storage for a single slimline water tank is 8,500 litres. Fortunately, there’s a way around this – just link up multiple tanks side by side to increase water storage capacity.
Please note: not all dimension combinations are available
Water Tank Dimensions
The right size water tank for you will depend on the rainwater storage capacity you need, as well as the space you have available. For a full list of all our Slimline Water Tank Sizes & Dimensions visit our Water Tank Pricing Page.
| Capacity (litres) | Width x Length x Height (mm) |
| 1,583 | 700 x 1600 x 1560 |
| 2,090 | 650 x 2200 x 1560 |
| 2,145 | 850 x 1800 x 1560 |
| 3,065 | 850 x 2100 x 1880 |
| 3,206 | 850 x 2600 x 1560 |
| 3,251 | 650 x 2800 x 1880 |
| 3,322 | 750 x 3000 x 1560 |
| 5,067 | 700 x 4000 x 1880 |
| 5,088 | 1150 x 2600 x 1880 |
| 5,119 | 1150 x 3100 x 1560 |
| 5,352 | 950 x 3200 x 1880 |
| 7,712 | 1150 x 3100 x 2350 |
| 8,523 | 1150 x 3400 x 2350 |
Round Water Tanks
Round water tanks can store up to 30,000 litres of water and are ideal where you have plenty of space and where you want a large volume of water – they’re a regular sight in country towns, where they’re helping farmers to combat drought, and significantly reducing the load on mains water supply in regional areas.
But if you’ve got a large-enough backyard, they’re a great choice for urban and suburban homes as well!
Please note: not all dimension combinations are available
Water Tank Dimensions
The right size water tank for you will depend on the rainwater storage capacity you need, as well as the space you have available. For a full list of all our Round Water Tank Sizes & Dimensions visit our Water Tank Pricing Page.
| Capacity (litres) | Diameter x Height (mm) |
| 2,071 | 1300 x 1560 |
| 3,120 | 1300 x 2350 |
| 3,138 | 1600 x 1560 |
| 3,324 | 1500 x 1880 |
| 4,903 | 2000 x 1560 |
| 5,332 | 1900 x 1880 |
| 5,336 | 1700 x 2350 |
| 7,814 | 2300 x 1880 |
| 10,308 | 2900 x 1560 |
| 10,635 | 2400 x 2350 |
| 10,768 | 2700 x 1880 |
| 15,015 | 3500 x 1560 |
| 15,126 | 3200 x 1880 |
| 15,528 | 2900 x 2350 |
| 18,095 | 3500 x 1880 |
| 20,108 | 3300 x 2350 |
| 20,484 | 2900 x 3100 |
| 22,619 | 3500 x 2350 |
| 23,407 | 3100 x 3100 |
| 24,942 | 3200 x 3100 |
| 25,278 | 3700 x 3350 |
| 29,838 | 3500 x 3100 |
One Big Tank or Several Linked Together?
It’s easier to transport and place smaller tanks, and we can place them in different locations to capture rainwater from different aspects or sides of a roof (or multiple roofs). One large tank will take up less space, but it can also mean that you can only capture the water from one roof location, limiting your harvesting capabilities.
From our many years of experience in supplying and installing water tanks, we have found that having three round tanks holding 29,000 litres each (total 87,000 litres) will easily keep even a large family in water all year round.
Can You Use Rainwater Tanks For All Your Water Needs?
80% of households with rainwater tanks consider the volume of water they collect in their tanks to be sufficient for all their needs, including:
- Drinking water
- Garden watering
- Toilet flushing
- Laundry usage
- Replenishing domestic pools or spas
- Car washing
- Supplying the hot water system
- Thermal buffers to insulate houses
- Ventilation for buildings
- Protecting homes from bushfires
Rainwater that you collect from a well-designed and operated system can be suitable for any and all domestic water uses. For example, you can use you tank water for your garden and some indoor uses (toilet flushing & showering), while still sourcing your drinking water from your water supply. And if you want to reduce your reliance on mains water even further, check out our Rainwater Tank Filter System which can make your tank water 100% safe for drinking as well.
Reduce Your Water Bills
| Household Size | Average Per year |
| 1 | $884 |
| 2 | $1,072 |
| 3 | $1,248 |
| 4 | $1,292 |
| 5 | $1,488 |
Buying A Water Tank
Is a water tank a good investment? How long does it take to pay your water tank back? All good questions. With around half of Brisbane homes having a water tank nowadays, water tanks are a trend that’s really caught on. And it’s not just about the environmental impact; they’re actually a great buy.
Let’s say that you spend $4,296 on a 3500 x 1560 round water tank with a 15,015L capacity (sounds oddly specific? That’s because it’s an actual water tank we sell – head to our pricing page). If you use 15,000L per month for 3 people, and you save $1,248 per year, your water tank will pay for itself in less than four years – and with a 30-year warranty, you can expect another 21 years of savings. #betterthanbitcoin? We think so!
Choosing The Best Water Tank for Your Needs
When considering a water tank, you may first ask, “What size water tank do I need?” But size is just one part of the equation. It’s also important to think about the materials, shape, and long-term value. While cost is a factor, keep in mind that cheaper materials like poly (plastic) can degrade more quickly, requiring replacement sooner. In contrast, steel water tanks offer greater durability, with a 30-year warranty, providing peace of mind and long-term savings on your water bills.
Why Choose Steel Water Tanks?
Steel water tanks are built to last, resisting cracking, UV exposure, and other environmental damage that can affect plastic tanks. This makes them a better investment for homeowners and businesses looking for reliability and sustainability. Select Water Tanks also offers fire water tanks, specifically designed to help protect your property during bushfire seasons. These tanks not only store water for everyday use but can be a critical resource when fire protection is needed most.
Fore more information on the benefits of Stainless Steel water tanks check out our article on Are Stainless Steel Rainwater Tanks Worth It?
Ready to find the perfect water tank?
Wondering, “What size water tank do I need?” Use our calculator to find the right size for your needs. Whether you prefer slimline, round, or fire water tanks, our durable steel tanks offer long-term savings and reliable protection – Contact us today for a free quote!