Natural pools are a type of swimming pool that use plants, bacteria, and natural materials to filter and clean the water without chemicals. They are also known as natural swimming ponds, organic pools, or biopools. They can have different designs and shapes and can be built from scratch or converted from an existing pool. They are a low-tech, ecologically diverse, and relatively inexpensive option that attracts wildlife and creates a natural pond-like environment
How do natural pools work?
Natural pools usually have two separate zones: one for swimming and one for water purification (also called the regeneration zone). The swimming zone is the area where people can swim and enjoy the water. The regeneration zone is the area where aquatic plants and biological filters remove harmful microorganisms and debris from the water.
The water flows from the swimming zone to the regeneration zone through a pump or a gravity system, and then back to the swimming zone through a skimmer or a waterfall. The plants also provide oxygen to the water and create a habitat for beneficial organisms.
What are the benefits of natural pools?
Some of the benefits of natural pools are:
- They do not use chemicals that can irritate the eyes, skin, or hair of swimmers.
- They are more environmentally friendly than conventional pools, as they use less water, energy, and resources.
- They blend in with the landscape and enhance the aesthetic appeal of the garden.
- They attract wildlife such as birds, butterflies, frogs, and dragonflies, creating a biodiverse ecosystem.
- They require less maintenance than conventional pools, as they do not need to be drained, cleaned, or refilled regularly.
- They can be enjoyed all year round, as they do not freeze in winter or overheat in summer
What are the challenges of natural pools?
Some of the challenges of natural pools are:
- They need more space than conventional pools, as they require a regeneration zone that is at least 30% of the swimming area.
- They may not be suitable for areas with extreme climates or soil conditions, as they depend on the health of the plants and the balance of the ecosystem.
- They may not meet the local regulations or codes for swimming pools in some regions, as they are still a relatively new concept.
- They may not appeal to everyone’s taste or preference, as some people may not like the idea of swimming in a pond-like environment with plants and wildlife
How to build a natural pool?
There are different ways to build a natural pool, depending on the budget, design, and location. Some of the basic steps are:
- Choose a spot that has even ground and lots of shade. Avoid a spot with tree stumps or shrubs that you will have to move. A shady spot will prevent algae growth and keep the water cool
- Section out a hole for the pool and an adjacent hole for the plant zone. The hole for the pool should be at least 45 to 50 square meters (480 to 540 sq ft) and 1 to 2 meters (3.3 to 6.6 ft) deep. The hole for the plant zone should be 10 to 20 square meters (110 to 220 sq ft) and 1 meter (3.3 ft) deep. The plant zone should take up at least 30% of the main pool area
- Dig the holes with an excavator or by hand. Make sure they have sloped sides and flat bottoms. Save any large rocks that you come across for later use
- Place a small water pump on the far end of the pool. This will help to circulate the water from the pool to the plant zone and back. You can also use solar panels or wind turbines to power the pump
- Line both holes with bentonite clay or synthetic liner. This will prevent water leakage and soil contamination. Make sure there are no wrinkles or gaps in the liner
- Fill both holes with water from a hose or a well. You can also use rainwater if you have a collection system. Check the pH level of the water and adjust it if necessary with vinegar or baking soda. The ideal pH level is between 6.5 and 8.5
- Separate the pool from the plant zone with a piece of black liner or mesh. This will allow water flow but prevent plants from floating into the pool area. You can also use rocks or logs to create a natural barrier between the zones.
- Add gravel, sand, or pebbles to both zones to create a natural substrate for plants and microorganisms. You can also use large rocks to create ledges, steps, or seating areas in the pool
- Add plants to the plant zone and around the pool. Choose plants that are native to your region and suitable for aquatic environments. Some examples are water lilies, iris, cattails, rushes, and sedges. You can also add floating plants such as duckweed or water hyacinth to provide shade and oxygen
- Add beneficial organisms to the pool such as snails, tadpoles, dragonfly larvae, and daphnia. These will help to control algae, mosquitoes, and other pests. You can also add fish such as goldfish or koi, but make sure they are compatible with the plants and the climate
- Enjoy your natural pool! Remember to monitor the water quality regularly and remove any debris or dead plants. You can also use a skimmer or a net to remove any floating leaves or insects.
How much does it cost to build a natural pool?
The cost of building a natural pool depends on several factors, such as the size, design, materials, location, and landscaping of the pool. Some of the general estimates are:
- The average cost of a natural pool is between $40 and $100 per square foot, but it can go up to $200 per square foot depending on the complexity and features of the pool
- The minimum size of a natural pool is usually 600 square feet, with half of that area dedicated to the plant zone. A pool of this size can cost between $50,000 and $90,000
- A larger natural pool with a total area of 1,400 square feet and a swimming area of 700 square feet can cost between $80,000 and $130,000
- A very large natural pool with a total area of 3,200 square feet and a swimming area of 1,600 square feet can cost between $130,000 and $200,000
- The cost of materials for a natural pool can vary widely, from $0.25 per square foot for a thin liner to $113 per square foot for a fiberglass liner. Other materials include gravel, sand, rocks, plants, pump, skimmers, and pipes
- The cost of excavation, machinery use, and labor can also vary depending on the site conditions, contractor rates, and local regulations
- The cost of landscaping and wildlife can add to the overall budget of the pool, as some homeowners may want to create a natural-looking environment around the pool with rocks, plants, waterfalls, lighting, and other features