There is a difference between plastics in a pool
When ordering a pool, it is easy to think that all pools are roughly the same except for size, color, and shape. At first, you might only focus on the aesthetics and consider how the pool will look in your garden. And that is good. But it is also worth thinking about what you want your pool to be made of. Is there a difference between plastics? Yes, the differences may be greater than you think.
Polyvinyl chloride (PVC)
Many of the pools sold in Sweden today are lined with a PVC liner, despite the Swedish Society for Nature Conservation advising against its use. Mainly because the base material in the plastic is actually hazardous to health. But also because so-called phthalates, are added to make the plastic softer. These substances are not only hormone-disrupting but also carcinogenic. And since they tend to leach out from the plastic into the water, they can also enter the body.
Therefore, the EU introduced a ban in 2015 on the use of these substances in the manufacture of PVC within the EU. So today's modern PVC materials should no longer contain this, IF they are manufactured within the EU, that is. Because legislation outside the EU is not as strict. So you should be careful to find out where your ordered liner comes from and also how old it is. Today's PVC production within the EU is regulated, but not the sales. So PVC made before 2015 can still be sold and used in pool manufacturing. And also PVC made elsewhere outside the EU. Therefore, be a bit critical and ask your pool supplier about which material they will use and where it comes from.
Polypropylene (PP)
Instead of lining their pool with a PVC liner, many today choose a PP pool. The pool is delivered as a pre-molded basin, which is lowered into an excavated hole in the ground. The plastic for these pools is usually polypropylene (PP). Hence the name PP pool.
Polypropylene is a strong and relatively environmentally friendly plastic that provides good insulation. This means that heat does not escape as quickly through the pool basin itself, and the water stays warmer longer. Otherwise, it is a lightweight material that is at the same time super strong and homogeneous. Therefore, it also resists scratches well and lasts a long time.
This plastic can be colored throughout and does not look like plastic once the pool is molded. Additionally, it is easy to shape so you can order stairs, benches, or whatever you want in your pool.
Unlike PVC plastic, it can withstand a lot of heat without changing. So in this type of pool, you can bathe in over 30 degrees if you want, without anything happening. The only thing that might happen over time is that it becomes a bit duller on the surface.
Fiberglass (polyester)
Fiberglass is also a plastic used when casting finished basins. The casting technique often gives softer lines. The material also gives a somewhat glassy and glittery surface. It thus gives a different impression than the PP pool's somewhat more elegant design. So it is, of course, a matter of taste.
The basin is built up of several layers of fiberglass, unlike a PP pool which consists of a single homogeneous material. Depending on how many layers are built and which materials are used for the different layers, the price and of course durability are affected. A pool with fewer layers and cheaper materials has a durability of 4-5 years, while a more expensive one may last 25 years. This should be compared to a PP pool, which can last up to 45 years.
Another thing to consider with a fiberglass pool is the risk of what is called “blistering.” Fiberglass is not completely waterproof. And when water penetrates the different layers, it leaves moisture that can lead to mold growth. After a while, the mold produces a gas that forms bubbles which expand and push out blisters in the fiberglass. This is commonly called blistering.
Another problem with fiberglass not being completely sealed is that water remains when it gets cold. And we all know what happens to water in winter. It freezes. And here comes the next risk. When water has penetrated the layers and stays there, there is a risk that the material freezes and breaks from the inside. And this is hard to avoid since water movement cannot be controlled or prevented. But the risk is of course reduced when the manufacturer mixes in denser materials. So find out carefully what the fiberglass pool you are looking at is made of. There can be a very big difference from one fiberglass pool to another.
As you now understand, there is a difference between plastics. And there is every reason to care about which one you choose, from many different perspectives. But with this overview, I hope you have a bit more information in your back pocket when discussing your purchase of a pool. Price is always important, of course. But there are also other things to consider. And once you have decided to invest, it might be comforting to make an active choice and select the one that lets you sleep well at night.
