Tuesday, 11 July 2023 Knowledge Articles

Are poly water tanks safe?

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The short answer is that polyethylene tanks are safe in every department. 

If you have any doubts about the safety of polyethylene water storage tanks, this article should dispel them. Poly water tanks are safe in every department and not harmful to your well-being. And no, they do NOT leach! 


Polyethylene is inert, and unlike highly alkaline concrete tanks, poly tanks don’t need to be flushed out with a full tank of water before you can use them. Promax poly tanks made from polyethylene certified to AS/NZS 4020: 2002 Potable (Drinking) Water Standard & AS/NZS 2070: Part 1 and Part 8 Australian Standards for Food Contact. That’s a technical way of saying that once the polyethylene is moulded into a tank, it can store potable water for human consumption. The water is not affected by heat, and ingress is impossible because the tanks are built to a standard with no allowance for cracking.  


As for the issue of a poly tank leaching chemicals and other substances into the water – it just doesn’t happen. As a chemically inactive material, food-grade polyethylene does not react with water. In contrast, concrete tanks leach lime and calcium into the water, resulting in harder water. People who have used concrete tanks before switching to poly tanks will say the water tastes different and wrongly attribute this to polyethylene leaching. It is not the case; instead, that “different taste” occurs because lime or calcium is no longer in their stored tank water! 


As a sustainable company, Promax applauds efforts to recycle and repurpose poly tanks at the end of their lives. However, old tanks are never re-made into new tanks. Every water tank is manufactured with 100% virgin polyethylene, yet another reason to be confident in the safety of poly tanks.  


While poly tanks are perfectly safe, you can further enhance the water quality by using rainwater harvesting accessories. For example, a First Flush Downpipe Diverter kit can be likened to a purifier; it diverts the contaminated water that washes off your roof with the first few millimetres of rainfall. The result is much cleaner water going into the tank. Inside your tank, a Floating Outtake floats on the water, drawing only the cleanest water from just below the surface. 


A poly tank is a safe tank. In conjunction with accessories like First Flush Downpipe Diverters and Floating Outtakes, the water inside your storage tank will be clean and ready to drink. No chemicals, no concerns and no leaching!   


If you have any questions or concerns about the safety of your poly tank give us a call and we'll ease your worries. 


Call Promax on 0800 77 66 29