Okay, I know this question has been asked before, but I can't find any information about this because of all the "RO Treatments" available to people instead of a drain/fill.
I have a pool in Cape Coral, FL. It is about 20,000 gallons. Like everyone else in the world, my wife and I don't like chlorine. We have looked into "swimming pond" conversions, as well as a lot of "chemical free" solutions that mostly seem like snake-oil.
In my business, we use a cheap ($1,000) reverse Osmosis unit that can produce about 2,500 gallons per day. My question is, could a unit like this be used on a pool to continuously or semi-continuously filter the water? The membranes and pre-filters should last an extremely long time once the pool is filled, as it would just be re-filtering RO water with the small amount of contaminants that make it into the water. The pool is covered and in a tightly screened area, so very little debris will make it in. There would never be children or anything else soiling the water beyond what happens just from going swimming. The system would also be "closed", meaning that the source of the water would be the pool (via a booster pump), and the output and wastewater drain would both empty into the pool.
I see a lot of advantages to swimming in RO water as well, since there are no minerals in it. RO also filters out bacteria and viruses very effectively. The water would also be almost completely free of organics for algae/bacteria to grow from. Theoretically, no type of complex organism or insect should be able to live in it, either.
I expect there is a perfectly valid reason why this isn't viable, and I'd love to hear it . I've never owned or maintained a pool before, so I am sure I am overlooking something.