Maintaining the right pH level in your pool is crucial for ensuring water clarity, comfort, and safety for swimmers. Traditionally, pool owners have relied on chemicals to lower pH levels, but these can be harsh and costly. Carbon dioxide (CO2) offers a more natural and sustainable alternative for pH control in pools.

The Science Behind CO2 pH Stabilization

When CO2 is introduced into pool water, it dissolves to form carbonic acid (H2CO3), a weak acid that naturally lowers the pH level of the water [1]. This process is gentler than using strong acids, which can be dangerous and corrosive. CO2 pH stabilization ensures that the pH stays within the recommended range of 7.2 to 7.8, preventing issues like scale formation, cloudy water, and damage to pool surfaces and equipment [1].

Advantages of Using CO2 for pH Control

1. Safety and Handling: CO2 is a colourless, odourless, non-flammable gas that is easy to handle and dose. Unlike mineral acids, it does not require special protective equipment and poses no risk of accidental chlorine gas production [2].
2. Gradual pH Reduction: CO2 provides a more controlled and gradual reduction in pH, making accurate control easier and safer for pool water chemistry [2].
3. Environmental Benefits: CO2 is a naturally occurring substance, making it an eco-friendly choice for pool maintenance. It reduces the need for harsh chemicals, which can cause skin and eye irritation [1].
4. Improved Process Control: Due to its natural buffering action, CO2 offers improved process control, contributing to the chemical equilibrium of the water without introducing secondary pollution [2].

 Considerations for CO2 Use

While CO2 is beneficial for most pools, it is not suitable for pools with high alkalinity or calcium hardness, nor for leisure pools and spas where water features can drive it out of the water [2]. Pool operators should conduct a risk assessment to determine the suitability of CO2 for their specific pool conditions.

Conclusion

Using CO2 for pH control in pools is a safer, more sustainable, and effective method compared to traditional chemicals. It ensures consistent pH levels, enhances swimmer comfort, and protects pool surfaces and equipment. By understanding the science behind CO2 pH stabilization, pool owners can make informed decisions to maintain optimal pool chemistry.

References

[1] The Science Behind CO2 pH Stabilization in Pools | Poolsmith

[2] Carbon dioxide for pH control (TN6) - PWTAG

Air Products is a global leading industrial gas supplier and specialists in swimming pool pH control systems. If you are interested in exploring how we could help you switch from chlorine to CO₂ and provide a safer swimming pool environment, please get in touch.