Available Colours
Available Colours
* Product May Vary Slightly. Polymaster will not be held liable for incorrect colour impressions, request your Polymaster colour sample to view colours. Polymaster tank colours represented match COLORBOND steel colours. *COLORBOND® and colour names are registered trademarks of Blue Scope Steel Ltd™.
RWT50KL
50,000L Round Water Tank
The 50,000L ‘Mega Tank’ (11,000 gallons) is our largest poly water tank in our range. Manufactured in one piece, it has no joins, seams or part lines and we do not remove the top of the tank for transport. All our rainwater tanks are UV stabilised and available in a range of 17 Colorbond® matched colours.
It will provide large capacity for farm storage or to increase your mains water supply for a wide range of household uses, from drinking water to garden irrigation to water for the laundry and bathroom.
When you invest in a poly plastic rainwater tank it’s important that you get one that lasts and is fit for purpose. Australian standards are put in-place to give households, peace of mind when it comes a tanks’ usability.
- Biggest single-piece poly tank in the range — 51,700L overflow capacity, no panels or on-site assembly.
- Outperforms two smaller tanks — more capacity, smaller footprint, one installation.
- Taller profile, stronger flow — 3.44m height delivers better gravity-fed pressure.
Get in touch
Need the right tank solution fast? Speak with a Polymaster expert today
Dimensions
Capacity:
50,000L (11,000 gallons)
Inlet Height:
3,290mm
Diameter:
4,600mm
Overall Height:
3,440mm
All measurements listed are approximate only
Standard Fit Out
Strainer Position:
12 o’clock
Overflow Position:
2 o'clock
Outlet size:
40mm (Brass)
Outlet Position:
6 o’clock
Strainer Size:
500mm
Ball Valve:
40mm
Guides & Specifications
Download Drawing
Installation Manual
Lifting Plan
Water Tank Category Brochure
When you invest in a rainwater tank it’s important that you get one that lasts and is fit for purpose.
Australian standards are put in-place to give households, peace of mind when it comes a tanks’ usability.
EXPERT SOLUTIONS
What makes Polymaster tanks the toughest?
- Self-supporting roof design means no support poles are necessary
- Extra thick walls for maximum strength
- Double strength UV+ resin ensures ultimate protection against the harsh sun
- One-piece construction with no joins, seams or part-lines
PRODUCT FEATURES
Highest Quality & Standards
Every tank is built to strict Australian standards, with quality fittings and components ensuring lasting performance and dependable, everyday water storage.
Ball Valve
Controls water flow at the outlet, letting you open or shut off supply quickly and reliably whenever it’s needed.
Brass Outlet
A durable, corrosion-resistant outlet fitting that connects to your plumbing or hose for reliable, long-term water access.
Lifting Lugs
Moulded into the tank for safer, easier handling during delivery and installation, without extra equipment.
Strainer
Filters debris and leaves from incoming water before it enters the tank, keeping stored water cleaner.
Overflow
Directs excess water safely away from the tank once it’s full, protecting the base and surrounding site.
Gallery
Explore Our Water Tank Gallery
See the 50,000L round water tank in real-world settings, from rural properties to rooftop and aerial views, showcasing its size, build quality, and Colorbond® finish across a range of installations.
FAQs
Frequently Asked Questions
Got questions about the 50,000L round water tank? Here are answers to some of the most common questions about durability, safety, and performance to help you choose with confidence.
Are round rainwater tanks and components weatherproof?
Yes — Polymaster rainwater tanks are fully UV resistant and built for Australian weather conditions. Components are carefully selected to ensure they’re protected and resistant to the elements.
Why choose one 50,000L tank instead of linking two smaller tanks?
One 50,000L Mega Tank delivers more capacity than two 22,500L tanks combined, in a smaller footprint — with a single installation, a single set of hook-ups, and no extra work joining tanks together.
What do your round water tanks weigh?
Weight varies with tank size and the number of fittings, but our round water tanks are comparable in weight to fibreglass or galvanised alternatives.
Is the smooth wall poly tank weaker than corrugated poly tanks?
This is a common myth. Wall strength comes down to material thickness and type, not the corrugated or smooth finish. Both designs offer similar strength — it’s a matter of aesthetics rather than durability.
What makes Polymaster worth it over cheaper alternatives?
One-piece rotomoulded construction means no seams to fail, and UV+ double-strength resin protects against cracking and fading. It’s built to hold its shape over time, rather than developing the visible sagging some cheaper tanks show with age.
How does the 50,000L compare to a steel tank of the same size?
The 50,000L Mega Tank gives you the same large-scale capacity as steel, without the rust, repainting, or liner replacement over its service life — one piece, one delivery, no on-site assembly crews.
Are round rainwater tanks and components weatherproof?
Yes — Polymaster rainwater tanks are fully UV resistant and built for Australian weather conditions. Components are carefully selected to ensure they’re protected and resistant to the elements.
Why choose one 50,000L tank instead of linking two smaller tanks?
One 50,000L Mega Tank delivers more capacity than two 22,500L tanks combined, in a smaller footprint — with a single installation, a single set of hook-ups, and no extra work joining tanks together.
What do your round water tanks weigh?
Weight varies with tank size and the number of fittings, but our round water tanks are comparable in weight to fibreglass or galvanised alternatives.
Is the smooth wall poly tank weaker than corrugated poly tanks?
This is a common myth. Wall strength comes down to material thickness and type, not the corrugated or smooth finish. Both designs offer similar strength — it’s a matter of aesthetics rather than durability.
What makes Polymaster worth it over cheaper alternatives?
One-piece rotomoulded construction means no seams to fail, and UV+ double-strength resin protects against cracking and fading. It’s built to hold its shape over time, rather than developing the visible sagging some cheaper tanks show with age.
How does the 50,000L compare to a steel tank of the same size?
The 50,000L Mega Tank gives you the same large-scale capacity as steel, without the rust, repainting, or liner replacement over its service life — one piece, one delivery, no on-site assembly crews.