Different water tank materials come with their own advantages and disadvantages. See the strengths and weaknesses of each type below.
Poly
Advantages
- Poly tanks come in many different sizes, shapes, colours, combinations and with multiple connection possibilities. They can go either above or below ground.
- Poly tanks are easier to transport, position or move according
to necessity. Their fast and easy installation means lower costs. - Poly tanks are lightweight but they are strong and durable, can withstand harsh climate conditions and are one piece construction meaning there are no seams to cause weak points. Rustproof material means longer life.
- Built in compliance to AS/NZS 4020 that involves testing of products for use in contact with drinking water.
- Poly tanks are the second cheapest (after metal), but because they out-last metal, they are more cost-effective.
Disadvantages
- At the end of their life-cycle (known to be more than 30 years), proper recycling is necessary.
- High Fire Risk – It is important to note that most tanks including poly tanks risk failure in a fire, just as any building, pump or pipework would, unless they are in a fire break zone.
Fibreglass
Advantages
- Fibreglass tanks are available in multiple sizes and work both above and below ground.
- Because the material is not metal, they will not rust.
Disadvantages
- Fibreglass material allows more light penetration, resulting in more algae growth.
- Require an external UV-resistant gelcoat which if damaged can reduce the life of the tank.
- Fibreglass is a brittle material that cracks much more easily than other materials. Fibreglass tanks require a food grade coating on the interior which is cured before sale. If damaged during the life of the tank it can expose the raw fibreglass which can release dangerous chemicals into the water
- Cost: More expensive than poly tanks
Concrete
Advantages
- Concrete tanks can be built above or below ground,available in different sizes and capacities, pre-cast and transported to the site or built on-site. They are long-lasting.
- They have maximum strength due to reinforced steel in the concrete.
- Rust resistant with little risk of corrosion.
- Cracks in concrete are fairly easy to repair with applicationsof waterproof paint, membrane or resin; however, these applications do not prevent cracking.
Disadvantages
- Concrete tanks are more expensive to build.
- Tanks are in permanent position.
- New tanks may leach out lime and other minerals thereby increasing the water pH and affecting the water taste.
- Concrete construction is energy intensive.
Metal
Advantages
- There are many sizes and capacities available and they can withstand harsh conditions including fire.
- They are the least expensive type, initially.
- Material is UV resistant
Disadvantages
- Metal tanks have a much shorter lifespan due to corrosion, different types of water may cause even faster corrosion. In these instances, adding a poly liner means a longer tank life but added expense.
- Corrugated steel tanks cannot be placed underground.
- Moving the tanks once they are in place is difficult. Liners used in Metal Tanks are comparatively very thin and the risk of the liner being pierced and failing is higher than all other tank types.
- Ground work before installation can be costly and involves extensive preparation when compared to other tank types.
For our blog post on the differences between different water tank types with images, click below:
Key Differences You Need to Know About Water Tanks