The Complete Guide to Installing a Poly Water Tank
- Leroy
- 4 days ago
- 3 min read
Installing a rainwater tank is one of the smartest investments you can make for your home or property. Whether you’re collecting water for the garden, topping up household supply, or boosting fire readiness, a well-installed poly water tank will give you years of reliable use.
Here’s a complete, step-by-step guide to help you get it right the first time — tailored to Australian standards and Tasmanian conditions.
1. Choose the Right Site
Your tank location affects everything — from water flow to delivery access.
Look for:
A level, stable area close to your roof downpipes.
Clear access for trucks or trailers during delivery (check gate widths and turning space).
A position away from large tree roots or falling branches.
Space for your pump, filtration system, and maintenance access.
Tip: Consider your future landscaping. Once full, a tank is extremely heavy and difficult to move.
2. Prepare a Solid Base
A strong, even base prevents your tank from sagging or warping.
For most poly tanks:
Use a compacted crusher dust pad, at least 75–100 mm deep.
The pad should extend at least 100 mm beyond the tank’s diameter on all sides.
Ensure it’s flat, level, and well-drained.
Other options:
Concrete base: ideal for larger tanks or poor soil conditions.
Tank stand: must be structurally engineered and suitable for the tank’s filled weight. The whole base of the tank must be supported to prevent distortion or failure.
Avoid placing the tank directly on clay, topsoil, or uneven ground — these can shift and cause stress cracks.
3. Ensure Correct Delivery & Placement
Before delivery day:
Confirm your site is ready and base complete.
Clear obstacles along the driveway or access path.
Decide whether you’ll require a roll-off delivery or position-on-pad service (ask your supplier).
Once on site, the tank should be placed gently upright on the prepared base — never dragged or dropped.
4. Connect Your Inlet & Overflow
Most tanks connect via your home’s roof downpipes. Use:
Leaf strainers to stop debris entering.
A first flush diverter to remove dirty initial runoff.
A PVC overflow pipe directed away from the tank base to prevent erosion.
Tip: Ensure your overflow is correctly fitted and directed away from the tank base to handle heavy rain without causing erosion or pooling.
5. Fit Your Outlet, Valve & Pump
Your tank will include a lower outlet fitting. Attach a:
Ball valve or tap for manual control.
Pump connection if you’ll be supplying garden hoses or household plumbing.
Quality pumps (such as Bianco or DAB) maintain consistent pressure for irrigation or domestic use. Use flexible hose connections to reduce stress on fittings.
6. Link Multiple Tanks (If Needed)
For larger setups, you can connect tanks with a balance line or manifold system:
Join tanks at the base so they fill and empty evenly.
Use poly pipe suitable for the application.
Install isolation valves for maintenance.
7. Secure & Maintain Your Tank
Once installed:
Check that the tank is sitting level and stable.
Strap or brace it if stored empty in windy areas.
Clean strainers and filters every few months.
Flush sediment from the base every few years to maintain water quality.
8. Know Your Local Regulations
Tasmanian councils may have guidelines on tank size, overflow management, or plumbing connections. Always check with your local authority or licensed plumber before connecting tank water to internal fixtures.
Final Checklist
✅ Site prepared and level ✅ Base compacted and wide enough ✅ Delivery access confirmed ✅ Inlet, outlet, and overflow installed correctly ✅ Pump connected with flexible hose ✅ Overflow directed safely away from pad
Built Tough for Tassie
At Global Poly Water Tanks, our tanks are AS/NZS 4766-certified, UV-stabilised, and designed to handle Tasmania’s cool winters and hot summers. Whether you’re setting up a compact garden tank or a 22,700 L rural system, we’ve got the right product and advice to make installation easy.