“Chemical-free water garden and swimming pools.
The plant portion, or regeneration zone, is separated from the swimming area by the wall seen a few inches below the water’s surface.
The pools have skimmers and pumps that circulate the water through the regeneration zone and back into the swimming area.
The aquatic plants filter out contaminants and use nutrients from the water as food which helps prevent algae.
Then rocks, such as granite river rock or haydite, to which friendly bacteria attach, act as biological filters…”