Water scarcity and water stress is a reality for South Africans; people are turning to water storage tanks to help with short-term solutions to minimise interruption of their water supply.
Water tanks are used to store large quantities of water for many different reasons, including agricultural irrigation, domestic and business use, fire protection purposes, rainwater collection and many more.
There are various materials with which a water tank can be made, the two most popular being poly plastic and steel. In this article, Abeco Tank’s COO, Mannie Jnr Ramos, discusses both of these materials, their advantages and disadvantages. In order to decide which water tank is the better choice for your usage, you will need to look at three key factors: cost (how much you can spend), capacity (how much water do you need to store) and location (where will the tank/s be placed).
Advantages of steel water tanks
While steel water tanks are more expensive than plastic tanks, they have a much higher capacity and are far more durable than plastic tanks.
Steel water tanks are perfect for customers who need to store anywhere from small sized tanks to much larger amounts of water. Steel tanks can hold up to 50 million liters of water, making them the superior tank for irrigation, industrial and fire protection purposes.
They are even more durable than plastic tanks, lasting approximately to50+ years, due to their resistance to environmental pressures like extreme temperatures and fires.
Because of their temperature resistance, steel water tanks are appealing as heat will not cause algae to grow in a steel water tank, making it a more hygienic choice especially where water is stored for purposes like drinking or bathing.
Their modular design allows greater versatility to customise tank sizes according to client requirements and site specifications. Compared to plastic tanks which only come in specific sizes - 1,000L 2,500L 5,000L, 10,000L and 20,000L - you cannot have in between sizes.
In summary, steel tanks are great for all uses including domestic and office use, however budget wise they are more expensive. For agricultural, commercial or industrial use, larger water tanks are far more suitable, making steel the far better choice.
Disadvantages of steel water tanks
Steel water tanks are expensive to produce and therefore is not a cheap option. However, they may be the cheaper choice in the long run due to their durability and resilience.
They are not available immediately and take 3-5 weeks to manufacture. They also require proper concrete foundations.
While the steel water tank has its downfalls, many of these issues can be avoided or dealt with easily. This water tank is ideal for all domestic, fire tank and potable water applications, but will not suit those on a tight budget.
Advantages of plastic water tanks
If you are looking for smaller volume options that are more cost-effective, plastic is the cheaper choice. Plastic water tanks are roughly 35% of the cost of a steel water tank.
They are inexpensive when it comes to transportation of individual tanks and because plastic tanks are already molded they are easier to install than steel tanks which require on site installation, thus they are easier and cheaper to move around or install than steel tanks.
Plastic water tanks can be bought at various hardware stores and building supply outlets as stock items.
Plastic tanks are offered in several colours but mainly green, black, blue and beige. Having said this, steel tanks can also be powder coated in different colours such as green, grey, beige and brown instead of being galvanised, putting them on par with plastic tanks from an aesthetic perspective.
Most plastic tanks last around 5-10 years, depending on whether they are exposed consistently to the sun or not.
Disadvantages of plastic water tanks
Plastic tanks serve a purpose but are limited in size and if you need to transport more than one it becomes an issue as you are basically transporting air. If several tanks are required transportation becomes costly.
That is why you will find plastic manufacturing plants all over the country. Whereas steel is stacked and assembled on site, so you can transport it a lot easier.
With plastic tanks, generally manufacturers make a few colours not colours to suit your needs.
Up to 40,000L, plastic tanks are a great alternative, but above this they are no longer an option; unless you are going to have 10 tanks next to each other. If a higher capacity is needed one would have to purchase a few plastic tanks and link them – versus purchasing one steel tank - to get the same amount of water required.
Location, as mentioned above, is also an essential consideration factor. Plastic tanks, particularly those darker in colour, are susceptible to UV heating. Warm water is the perfect breeding ground for algae, which means that plastic tanks are not ideal for domestic use or for storing drinking water. However, this issue can be avoided by purchasing a self-cleaning water tank, which would still be cheaper than a steel tank that requires thorough manual cleaning.
All in all, both steel and plastic water tanks have benefits and pitfalls. The best choice is entirely dependent on its intended use and location. While plastic water tanks are cheaper, aesthetic, readily available and easier to transport they are only suitable for households and small businesses. Steel water tanks are suitable for mining, power generation, processing & manufacturing and public buildings such as office blocks, apartment blocks, shopping centres, hospitals and schools. Steel tanks are also less likely to become infected by any outside pollutant. Both types of water tanks are useful in their respective ideal conditions, thus careful consideration needs to be done and thorough comparisons need to be made before purchasing a water tank.