Once the menu is open you can move between options with the arrow keys and select an option with the enter or space keys. Typeahead search is also available.
logo Go to Home Page

pH Control for Swimming Pools

pH control in pools with carbon dioxide

Certain diseases can be transmitted through contaminated pool water. This is why swimming pools need to be disinfected, preferably with solutions that will not affect the pool users nor the environment.

The most widely used method is chlorination with sodium hypochlorite. However, it has its limitations. If the pH of the pool water is not kept between 7.2 and 7.6 the chlorinated water could cause eyes, skin and mucous membrane irritation to the pool users. At the same time, it would also become corrosive to pool's equipment.

Historically, pH control has been carried out with harsh solvents (mineral acids) that can be dangerous to handle. Carbon dioxide offers a clean and safe alternative for pH correction. When dissolved in water, CO₂ reacts to form carbonic acid, a weak acid capable of safely reducing the pH to the desired value. Recuperated from natural processes, it is also an environmentally friendly solution.

Download CO₂ – pH Control in Pools brochure

​Benefits of Using CO₂ as a pH-reducing Agent

Chlorine Gas Fumes removal

The risk of chlorine gas fumes produced by an accidental reaction between a strong acid and hypochlorite is eliminated

Less Maintenance Costs

Risks handling strong acids is eliminated. Lower maintenance costs as no corrosion is caused by strong acids

Precise pH Control

Over-acidification risk is eliminated as the reduction in pH is more gradual than with mineral acids, enabling more precise control of the pH

Reduced Chloramines Generation

There is a 30% reduction in oxidant levels, which is especially important at the water surface level

Interested in learning more about pH control in pools?

Our experts will work with you to design the best solution for your needs.


The Equipment Needed to Supply and Dose the CO₂ Consists of:

  • CO₂ tanks (cylinders, dewars, etc.)
  • A CO₂ pressure and flow regulation system
  • Automated pH control
  • CO₂ diffusion system
  • Pipes from the CO₂ storage to the injection point
Learn More


Air Products gases, typically provided in gaseous and liquid form, enable customers in a wide range of industries to improve their environmental performance, product quality, and productivity.

Carbon Dioxide

Our experienced applications teams across the globe can use their industry and application knowledge to provide you with a compressed or liquid carbon dioxide supply and technology solution to meet your unique needs.