We've answered this question thousands of times over the years, and these days, hundreds of prospective rainwater tank buyers will ask us for quotes every year -- and many will raise the question in the first few minutes of our conversations. 

We get it. 

Price matters (it's not the only consideration, but it is pretty important). Price often dictates what type of rainwater tank, and any accessories, you might get. You need to develop an initial budget and plan for any long-term ownership costs, and that's true for any tank, at any size, in any configuration you might want. 

At Rapid Plas, we strive to educate every prospective buyer, even if that leads you towards a different brand or type of rainwater tank. I'll do my level best to offer some genuine reasons on what makes some tanks more expensive and others cheaper.  

Every poly rainwater tank brand has a slightly different shape, style, or look. This is not the major difference however as no matter what the looks of the tank are, they at the end of the day, all hold water (or are certainly meant to). 

The real questions are how they are manufactured, how long they last, are there maintenance costs over the short to medium to long term? and are there issues that crop up that I might not be aware of? 

Watch a video of a rainwater tank being made on our videos page

Watch here 

Cooking a rainwater tank 

The process of cooking a rainwater tank is one of the most critical, and while I’ll try and refrain myself from getting too deeply into the science of the process, it is too important not to have some understanding of how it works. A poly rotationally molded product must be cooked at the right temperature, for the right amount of time with the temperature increasing and decreasing at the right times throughout the cook. Very simply with this step not performed precisely the product can either be overcooked and become brittle or be undercooked which prevents the poly molecules bonding together causing a weakness in product.  

Cooling a rainwater tank 

The process of cooling a rainwater tank is probably one of the most misunderstood steps of the manufacturing process. Its easy to rush this step and remove the tank from its mold way to early, before its properly cured, so as to get the mold back into production as soon as possible. As many would understand they are businesses manufacturing these products with labour, raw material, electricity and gas costs that need to be managed, but overlooking this step to save on costs can greatly reduce the quality, longevity and performance of a rainwater tank. If a tank is not allowed the time and correct cooling requirements to completely cure it becomes a very inferior product.  

What raw material is used 

This one you’ll find is difficult to really find out what material a brand of tank is made of. Is it LLDPE? (linear low-density polyethylene) Is it processed and ground properly under controlled conditions. Without the right raw material, you cannot make a quality rainwater tank. Does the manufacturer have 100% control over how the material is processed (colour added) and ground to a powder?  

Design specifics 

While the look and style of the design of rainwater tanks seems to be purely aesthetic, it has serious implications to its structural integrity. For example, the radius of all angles built into the steel mold could either be too tight, which can cause a potential to crack in the future, or too large in which case the finished product changes from the desired shape in which it was designed. Some tank designs have ribs or beams in the walls or roof which are theoretically there to provide extra strength, but if these are compromised with incorrect degrees of radius, they can in fact weaken the tank.  

How long will a tank last? 

To answer this honestly, I’ve got to say that it depends very much on whether the above points are performed correctly. If they are a poly tank should last at least 30 years. There are some tanks out in the field that have been there for 30 years and are still going strong. The Australian sun does after time cause the tank roof to fade, even with the best UV protection built into the raw material. This is very similar to the roofing iron of a house which, you might have noticed, does seem to fade quite quickly.  

Maintenance issues and costs 

Obviously, there’s the upfront cost of the tank itself and the installation. With maintenance, you want a tank with the lowest maintenance cost possible. One of the most important items to help reduce maintenance costs is the algae protector cover. This simply stops sunlight getting into your tank, and its light that causes algae to grow. Cut out this issue and you quickly remove a maintenance nightmare. Regularly removing and cleaning out the strainer where the water comes in is also an important task, so ensure you choose a tank that allows you to do this with ease.  

Probably one of the most serious issues that can cost the most is how the overflow is installed. If the water runs out and begins to wash away the base your tank is sitting on, the structural integrity of the tank becomes effected. So, to have a tank where you can plumb the overflow out any point around the tank that you wish, can both save you time and money on installation and on maintenance costs.   

What the tank comes with 

Will your tank come with just the standard inclusions to help you get set up quickly and easily? Having to add extra outlets once you receive your tank or having to purchase something as simple as a ball valve, can add significant cost to the installation project. While no poly rainwater tank comes with everything you need for your specific configuration or requirements it is good to know what you are getting upfront.  

Summary 

In summary, while there is much that can cause an inferior rainwater tank to be manufactured, from the design itself, the raw material, to the process of manufacturing, there are many top quality and successfully made poly rainwater tanks installed across QLD and NSW. I just thought it prudent to help lead you to make an educated and informed decision. Trust this helps.