Natural Swimming Pools

found on houselogic.com:  Natural Swimming Pools: 9 Myths Busted

Natural pools use one of two types of biological filters to create water that’s clear, clean, and chemical-free. Water is circulated by pump through either a gravel filter or a plant filter, depending on your preferences and, to some degree, your climate (gravel filters are better in warmer climates). Maintenance is easy: Once a month, remove any loose sediment with a pool vacuum cleaner.

You can build a natural swimming pool that’s a dead ringer for aregular pool, complete with concrete sides and bottom, and a traditional sky-blue pool color. You can even substitute an out-of-sight gravel filter for the plant pond.


Sterilized soil is good for the plant pond, but for the swimming pool, you can use concrete, a synthetic or rubber liner, or bentonite clay. At about 35 cents per sq. ft. (not installed), a 3-inch-thick layer of waterproof bentonite is the cheaper option. Adding 3 to 4 inches of pre-washed gravel to the bottom of your plant pond provides a habitat for beneficial bacteria that biodegrade any organic materials.

Any animals attracted to your natural swimming hole, such as dragonflies and frogs, keep to the plant side of the system, which is their natural habitat. And yes, you want them: They eat mosquitoes and their larvae, keeping your backyard free of biting pests. 

Most natural swimming pools feature two connected pools — one for swimming, and a shallow pool to hold plants. The root structures of aquatic plants — cattails, water lilies, and duckweed — remove bacteria and other contaminants. Check your state extension service for localized water plants.