How to Build and Maintain a Bio Swimming Pool

How to Build and Maintain a Bio Swimming Pool

Bio swimming pools, also known as natural swimming pools, are an eco-friendly alternative. They use biological processes to maintain water purity. Unlike traditional pools, they don’t rely on chemicals. This makes them healthier for swimmers and the environment.

If you’re considering a bio swimming pool, this guide will help. We’ll cover everything from planning to maintenance.

Planning Your Bio Swimming Pool

Research and Design

Firstly, research is crucial. Understand the basics of bio-swimming pools. They consist of a swimming zone and a regeneration zone.

The swimming zone is for swimming, while the regeneration zone filters the water. This setup mimics natural water bodies. Consider the size and shape of your pool. Additionally, plan the location carefully. It should receive ample sunlight, which helps plants in the regeneration zone.


Secondly, budget planning is essential. Bio swimming pools can be more expensive initially. However, they save costs in the long run. They require less maintenance and no chemicals.

Include costs for excavation, materials, plants, and professional help. Compare prices from different suppliers. Also, consider the ongoing maintenance costs.

Professional Help

Although DIY is possible, professional help is recommended. Experts ensure proper design and construction. They understand the complex biology involved.

A well-built pool functions efficiently and lasts longer. Look for professionals with experience in bio swimming pools. Check their credentials and customer reviews.

Building Your Bio Swimming Pool

Excavation and Construction

Once planning is complete, start with excavation. Mark the area according to your design. Excavate both swimming and regeneration zones. Ensure proper depth for both zones.

The swimming zone should be deep enough for swimming. The regeneration zone can be shallower. Install barriers to separate the two zones. These barriers prevent plant roots from spreading into the swimming area.

Lining the Pool

After excavation, line the pool with a waterproof membrane. This prevents water leakage. Use a durable, UV-resistant liner. Secure it properly to avoid wrinkles.

Additionally, consider adding an underlay for extra protection. The lining is crucial for maintaining water levels and preventing seepage.

Installing Filtration System

Next, install the filtration system. Although plants do most of the filtration, mechanical filters help.

A skimmer removes debris from the surface. A pump circulates water between the zones. Ensure the pump is energy-efficient. Position it to maintain a natural water flow. This keeps the pool clean and clear.

Planting the Regeneration Zone

Now, focus on the regeneration zone. Choose aquatic plants that thrive in your climate. Plants like water lilies, reeds, and sedges are common. They absorb nutrients and provide a habitat for beneficial microorganisms.

Arrange plants at different depths for a natural look. Ensure they cover at least 50% of the regeneration zone. This maximises their filtering efficiency.

Filling the Pool

Once everything is in place, fill the pool with water. Use untreated water to avoid chemicals. Rainwater or well water is ideal. Gradually fill the swimming zone first. Then, fill the regeneration zone.

Check for any leaks or issues during filling. Ensure the water flows naturally between the zones.

Maintaining Your Bio Swimming Pool

Regular Cleaning

Maintenance is key to a healthy bio-swimming pool. Regular cleaning keeps the pool in top condition. Use a pool skimmer to remove floating debris. Check the bottom for settled debris and remove it.

Clean the mechanical filters regularly. This ensures they function properly. Also, monitor the water level and refill as needed.

Plant Care

Plants play a vital role in bio-swimming pools. Therefore, they need regular care. Remove dead or decaying plant material. This prevents nutrient buildup.

Trim overgrown plants to maintain balance. Replace any plants that aren’t thriving. Healthy plants ensure effective water filtration.

Water Quality Monitoring

Regularly monitor the water quality. Test for pH, nitrates, and phosphates. The ideal pH is between 6.5 and 8. Excess nitrates and phosphates can cause algae blooms.

If levels are high, take corrective actions. Add more plants or reduce feeding if you have fish. Clearwater indicates a healthy pool.

Managing Algae

Algae can be a problem in bio-swimming pools. However, they can be managed naturally. Introduce algae-eating fish like minnows.

Add more plants to outcompete algae for nutrients. Ensure the pool receives enough sunlight. Shade can encourage algae growth. If algae persist, consult a professional for advice.

Seasonal Maintenance

Each season requires different maintenance tasks. In spring, clean the pool thoroughly. Check plants and add new ones if needed. Summer is the peak swimming season.

Regularly clean and monitor the pool. In autumn, remove fallen leaves and debris. Prepare plants for winter. In winter, reduce maintenance but keep an eye on water levels.

How to Build and Maintain a Bio Swimming Pool

Benefits of Bio Swimming Pools

Environmental Benefits

Bio swimming pools offer numerous environmental benefits. They reduce the use of harmful chemicals. This protects local water bodies and wildlife.

They also create a natural habitat for plants and animals. This promotes biodiversity. Additionally, they use less energy than traditional pools. This reduces your carbon footprint.

Health Benefits

Bio swimming pools are healthier for swimmers. They don’t cause skin or eye irritation. There are no chemical fumes to inhale. The natural environment is relaxing and stress-relieving. Swimming in clear, chemical-free water is a unique experience. It’s like swimming in a natural lake.


Although initially expensive, bio swimming pools are cost-effective in the long run. They have lower maintenance costs.

You save on chemicals and energy bills. Plants are a one-time investment. They grow and maintain themselves. Over time, the pool pays for itself.


Building and maintaining a bio swimming pool is rewarding. It requires careful planning and ongoing maintenance. However, the benefits outweigh the efforts. You’ll enjoy a natural, eco-friendly swimming experience.

Your pool will be a haven for wildlife. Moreover, you’ll contribute to environmental conservation. Embrace the idea of a bio swimming pool. Enjoy the harmony between nature and recreation.

Tony Augustine

About the author

In 2012, I helped establish KJA & Sons and have been deeply engaged in many swimming pool initiatives ever since. My expertise lies in designing filters for chlorine-free swimming pools, as well as living water gardens, koi fish ponds etc.