Plastic water tanks certainly have many
advantages over tanks made from other
materials, assuming that good quality
poly water tanks are selected.
A local South African supplier
cautions against cheap plastic water
tanks that “may last a year if you’re
lucky” and warns that they may leach
harmful chemicals into the stored
drinking water. For the South African
climate, they recommend polyethylene
storage tanks of a high quality, and being
rotational moulded.
Plastic vs steel tanks: Plastic or
polyethylene tanks are lighter, easier
to transport, do not rust or corrode
and, while reasonably less expensive
than coated steel tanks, they are much
less expensive than stainless steel
tanks. Rotational moulded poly tanks
do not have the seams that steel tanks
do. Seams can rust, corrode and are
sometimes weak spots where cracks
and splits can occur.
Plastic vs fibreglass tanks: As the tank
walls are fairly rigid in fibreglass tanks
Plastic vs concrete tanks: Concrete
tanks need extensive technical know-
how to build and install correctly. If not
properly built or installed, concrete tanks
can be plagued by leaks from cracks
and an improperly sealed interior. The
cost of concrete tanks is also relatively
high. They can be prone to chemical
erosion in some environments and are
usually considered where the amount
of water storage capacity far exceeds
what normal poly water tanks could
handle (for example a municipal water
storage facility).
Plastic vs wood barrels: Although this is
not a common comparison, many wood
barrels are being offered as rain barrels
or rain drums. Aesthetically, an oak
rain barrel may be better than a plastic
or polyethylene drum version, but may
suffer from wood rot, is difficult to keep
clean, and may be less hygienic than the
plastic drum equivalent. u
Plastic tanks also affect
the biological properties
of water where different
microorganisms grow and
multiply at a faster rate
compared with clay or
cement tanks.
References
1. Toqeer Ahmed & Saeed Ahmed
Asad. (2015) ‘Safe water: Is your
plastic container poisoning your
water?’ Dawn. Accessed on: 5 April
2015.
2. Eco Water. ‘Water Tanks, Plunge
Pools & Utility Cabins’
www.ecowaterconcretetanks.com.au
3. Tanks Direct. ‘The Disadvantages
of Concrete Storage Tanks’
www.tanksdirect.com/blog/
disadvantages-concrete-storage-
tanks
4. Aqua dam. www.aquadam.co.za
5. Rain harvest. ‘Water tanks: What’s
best – plastic, steel, fibreglass,
concrete or wood?’
www.rainharvest.co.za/2014/06/
water-tanks-whats-best-plastic-
steel-fibreglass-concrete-or-wood
Water Sewage & Effluent September/October 2017
33
technology
Plastic perfection
and they are heavier than plastic tanks,
they are more prone to cracking. Owing
to the minute gaps between the fibres,
fibreglass tanks allow more sunlight to
enter. As the manufacturing process of
building good quality fibreglass tanks is
time-consuming and thus costly, it works
out more costly than equivalent quality
plastic tanks.
But before you make up your mind and
believe that plastic storage tanks will be
the death of you, here is the argument
for plastic tanks …
Wood barrels, while not common in South Africa and being aesthetically pleasing, can become home to a host of parasites.