I have a natural pool in south east Australia. It is at its best in summer where temperatures can exceed 40c
I recently had the water tested by my local council which came back with a very healthy score card. This summer is the seventh for my pool and absolutely nothing has ever been added to the water to treat it.
There is approx 230,000 litres in the system which is circulated by a single 460 watt pump. Water clarity is excellent.
I built 2 pools last year that run on solar power only. One has a single 100 watt pump, and the other has two 100 watt pumps.
Both pools are producing the same healthy, clear water as my own pool.
The concept for these pools is very simple, it is a matter of understanding what is required, and why. The other requirement is to know how to build a solid construction that will last for years.
I use Firestone liner from the U.S. which has a 25 plus year life span.
The name 'natural pools' came from Europe and refers to the swimming experience, not the construction. A well built natural pool will exceed all but the most pure streams and lakes because they are a closed system with no runoff from land where animals and fertilizers etc are present.
There is nothing wrong with a blue tiled, dead water pool if that is your preference, but after experiencing my own pool, it is hard to beat.
I can also drink the water from my pool, which has a better taste than my rainwater tank.
The pool chemical market is huge, I can only chuckle when I go to a pool store to buy plumbing fittings, and look at the 'great wall of chemicals' on offer.
Most importantly, there are no special components needed to be bought to make these pools work. My own systems are built using 'readily available to the public' components.
Find out how and why fish tanks and aquaculture systems work, and you will be well on the way to understanding the concept.