First pioneered decades ago by Austrian company BIOTOP, natural swimming pools contain water that is self-cleaning and free of any salt or chemicals. Unlike traditional swimming pools, the water is “living”: a variety of plants and life forms live within it and contribute to its maintenance.

“It becomes a very controlled pool and it looks just as clean and clear as a pool that’s been sanitised,” Natural Swim Pools owner Wayne Zwar said, who has installed about 40 of these pools over the last five years.

There are two types of natural swimming pools. The first, which Zwar refers to simply as “natural pools”, feature a “regeneration zone” next to the pool that contains gravel beds with plants that help clean the water.

For those who want their pool to look as much like a traditional swimming pool as possible, or don’t have room for a regeneration zone, the other option is the “living pool”, which uses an underground filter to create the same thing completely chemical-free. These can either incorporate elements such as rocks and plants (meaning a little bit of friendly algae) or look just like a regular, structured pool.

And while birds, plants and insects can thrive in natural pools, mosquitoes are a non-issue due to the constant flow of water (mosquitoes are only attracted to stagnant water).

Natural pools are also much more energy efficient as they don’t require high-power filtration pumps.

“Pools themselves aren’t sustainable,” Kulja Coulston from the Alternative Technology Association said. “People are trying to change that. By using natural pools they’re not using chemicals, but they’re also creating natural habitats. They’re pools that are a luxury item while actually giving back. I would expect that natural pools would be on lots of people’s radars in coming years.”

At this stage the biggest drawback is the cost: BIOTOP pools cost about $80,000 to install, while traditional pools can be converted into natural pools for upwards of $25,000 (plus installation). After this initial outlay, however, owners save thousands of dollars a year on energy bills and buying chemicals.

For those who have made the natural pool leap, there’s no turning back. “It’s like swimming in freshwater lakes or rivers – you can’t compare that to chemical pools,” Zwar said.

“And you’re sitting there mesmerised by the dragonflies, and the frogs, and everything else that moves in or on the product and creates this incredible oasis … That’s pretty special.”

This is an edited version of a story that first appeared on domain.com.au