Water tanks: steel, fibreglass, plastic…which type to buy?

When it comes to choosing a water tank, there are a bewildering number of types, sizes and brands to choose from, varying from cheap, inferior tanks to very expensive, high quality tanks.  There needs to be a balance of price, quality as well as longevity and a few other factors must be considered.  It does not make sense to base choices solely on price as inferior ‘made in China’ tanks will not last long and may even be hazardous to your health.  This is article discusses the merits and negatives of water tanks made from steel, fibreglass and ‘plastic’ (actually polyethylene).

Steel water tanks

Steel water tanks can be divided into two types: stainless steel tanks and coated mild steel tanks.  Stainless steel water tanks are generally of very high quality with a commensurate high price tag.  Stainless steel tanks are corrosion resistant (depending on the grade of stainless steel used) and not much maintenance is required.  However, stainless steel water tanks, apart from being extremely expensive, are heavy and difficult to transport & install, prone to denting during transport and are not commonly available in many different capacities.  Some grades of stainless steel can be brittle and can crack under impact.

Water tanks made from mild steel must be galvanized or coated to protect against corrosion.  Galvanised water tanks generally last quite a long time but can suffer from corrosion at joints/welded areas after a few years.  If corrosion/rusting occurs along welded seams and is not detected, the tank could develop leaks.  Coated mild steel water tanks’ longevity depends on the type of paint/coating applied to the surfaces and generally need to be re-coated/painted periodically.  The inside of steel tanks must be coated with a food-grade lining to ensure water is stored safely.  The mineral content of water to be stored in mild steel water tanks must also be considered as corrosion may be accelerated depending on the chemical/minerals in the water (service life can be reduced to only a few years).  Mild steel water tanks also share the disadvantages of stainless steel but are considerably less expensive.

Fibreglass water tanks

Most fibreglass water tanks on the market are generally of good quality and long-lived but are still relatively expensive.  Compared to plastic or polyethylene water tanks, fibreglass water tanks are heavier and are not available in the range of colours and sizes that plastic tanks can be found in.  Fibreglass water tanks can also be prone to cracking if roughly transported and installed or if impacted; some fibreglass tanks are very brittle.  Fibreglass water tanks also tend to allow more light into the interior which encourages algae growth.  Fibreglass water tanks are more fire-resistant than polyethylene water tanks but not as fire resistant as steel water tanks.

Plastic or polyethylene water tanks

Polyethylene tanks are, in many cases, the best choice for many domestic and industrial purposes and their few disadvantages are outweighed by there many advantages.  First and foremost, choose a poly water tank from a trusted brand and do not base your choice on price alone.  The cheapest plastic tanks are generally of inferior build and may not even last a year (especially the type with thin walls and that have joining seams).  Ensure that the polyethylene is made from food-grade, UV-protected material and that the manufacturer offers a guarantee.  Good quality plastic water tanks are light, easy to transport and install, do not rust or corrode, fairly impact resistant, affordable and can have surprisingly long service lives (up t0 25 years, depending on environmental conditions).  Plastic water tanks normally has a very smooth interior which is easier to clean thank tanks made from other materials.  Plastic water tanks are also available in wide array of colours and sizes and there are plastic tanks designed for underground installation too.  When a ‘plastic’ water tank has reached the end of its useful life, it can be recycled too.

In South Africa, we recommend water tanks made by JoJo Tanks, see why by reading Water Tank Brands: Quality vs Price…There is a difference.

JoJo Tanks South Africa offer a wide range of products such as plastic water tanks and chemical tanks to suit every household, business or agricultural need, including silo tanks and silo tank stands as well as other high quality JoJo Tanks products.  See JoJo Tanks’ VERTICAL TANKS, HORIZONTAL TANKS (transporter tanks), STEEL TANK STANDS and OTHER JOJO PRODUCTS and see JoJo Tanks’ NEW 6000 LITRE UNDERGROUND TANKS. Also see our FAQ and WATER TANK PRICES.