This article was originally published on 12th March 2019 and has been updated to reflect the latest industry research.
Water clarity, swimmer comfort, and equipment longevity all depend on the precise control of dissolved gases in swimming pools. Yet, many pool operators focus solely on pH and chlorine levels, overlooking how gases like carbon dioxide (CO₂), oxygen (O₂), nitrogen (N₂), and chlorine (Cl₂) influence water chemistry.
Excess dissolved gases can lead to pH imbalances, corrosion, cloudy water, and inefficient disinfection. In poorly managed pools, these issues can escalate into costly maintenance problems or even health hazards. Understanding dissolved gas dynamics and deploying the right analytical tools is essential for maintaining a stable, healthy pool environment.
To address these challenges, dissolved gas analysis (DGA) provides a reliable way to monitor and regulate gas in pools. Among the most effective methods, mass spectrometry-based dissolved gas analysis offers unmatched precision and real-time insights. The HPR-40 DSA from Hiden Analytical, a membrane inlet mass spectrometer (MIMS), detects dissolved gases at exceptionally low concentrations. By applying this system, pool operators can take a more data-driven, scientific approach to water quality management, ensuring more efficient chemical use and long-term equipment protection.
How to Perform Dissolved Gas Analysis in Swimming Pools
Monitoring and managing dissolved gases is not just about maintaining clear water. Instead, it’s about preventing chemical imbalances, ensuring effective sanitation, and protecting pool infrastructure. Accurate dissolved gas analysis provides the data needed to make informed adjustments. Moreover, performing regular dissolved gas analysis allows operators to proactively address water chemistry issues before they escalate.
1. Routine Water Testing for Dissolved Gases
Standard water testing methods provide insights into dissolved gas levels and their impact on pool chemistry. Key tests include:
- pH and alkalinity measurements to assess CO₂ balance.
- Dissolved oxygen (DO) sensors to monitor corrosion risks.
- Oxidation-reduction potential (ORP) testing to evaluate chlorine efficiency.
- Turbidity and microbubble observation to detect excess gas saturation.
Although these methods offer a basic understanding of dissolved gases, mass spectrometry provides a more advanced and precise approach to analysis.
2. Aeration and Degassing to Manage Gas Levels
Pools with high CO₂ levels or gas supersaturation benefit from controlled aeration or degassing.
- Aeration methods – Waterfalls, fountains, or air diffusers can strip out excess CO₂, raising pH naturally without chemicals.
- Vacuum degassing – This technique removes trapped gases before they form bubbles, improving water clarity and filtration efficiency.
Effective aeration and degassing, supported by dissolved gas analysis, help maintain proper water chemistry and prevent issues caused by excessive dissolved gases.
3. Optimising Circulation and Filtration to Prevent Gas Buildup
Proper water circulation, combined with dissolved gas analysis, prevents gas imbalances by evenly distributing dissolved gases and minimising areas of stagnation. Key strategies include:
- Regular pump and filter maintenance to avoid air pockets and cavitation.
- Adjusting return jets to prevent pressure fluctuations that contribute to gas bubble formation.
- Optimising flow rates to minimise rapid gas release from high-speed jets.
Poor circulation can lead to localised gas accumulation, resulting in uneven water chemistry and inefficient disinfection. Regular dissolved gas analysis can help identify circulation-related gas buildup before it becomes a problem.
4. Using Chemical Dosing Strategies to Regulate Gas Levels
The way chemicals are introduced into pool water influences dissolved gas behavior. Best practices for chemical management include:
- Slow acid or chlorine addition to prevent sudden gas release and pH swings.
- Pre-dilution of chemicals to avoid localised gas saturation that can lead to scaling or cloudiness.
- Automated dosing systems to maintain stable chlorine and pH levels while minimising gas disturbances.
Proper chemical dosing, guided by dissolved gas analysis, ensures dissolved gases remain at optimal levels. This can prevent problems like excessive CO₂ buildup or chlorine gas imbalances.
Advanced Dissolved Gas Analysis with Mass Spectrometry
Traditional testing methods provide useful data. However they often lack the precision for a full understanding of dissolved gas behavior. Mass spectrometry is a highly sensitive, real-time technique that enables pool operators to measure gas concentrations with extreme accuracy, identifying even the smallest fluctuations before they cause issues.
The HPR-40 DSA from Hiden Analytical is a membrane inlet mass spectrometer (MIMS) specifically designed for dissolved gas analysis in aquatic environments. Unlike standard sensors, which may only detect specific gases, mass spectrometry allows for the simultaneous measurement of multiple dissolved species, including CO₂, O₂, Cl₂, and harmful disinfection byproducts (DBPs).
Why Use the HPR-40 DSA for Pool Water Monitoring?
- High Sensitivity: Detects dissolved gases at sub-ppb (parts per billion) levels.
- Real-Time Analysis: Provides immediate insights into gas fluctuations.
- Multi-Species Monitoring: Simultaneously tracks CO₂ and O₂.
- Configurable Sampling Options: Adaptable for different pool systems, with flow-through and dual-probe membrane inlets.
Utilising mass spectrometry for dissolved gas analysis provides DGA results with sub-ppb precision, allowing pool operators to maintain exact control over water chemistry and prevent costly maintenance issues before they arise.
Smarter Solutions for Pool Water Quality
Dissolved gas analysis is a crucial part of effective pool maintenance. Ignoring it can lead to fluctuating pH, inefficient chlorine use, and equipment damage. What seems like a minor imbalance can quickly escalate into costly repairs and swimmer discomfort.
A combination of regular testing, optimised circulation, aeration, and controlled chemical dosing provides a strong foundation for maintaining water quality. To take precision a step further, mass spectrometry-based dissolved gas analysis offers real-time data and greater control over water chemistry, helping operators stay ahead of potential issues. With this solution, facilities can maintain clear water, effective sanitisation, and long-lasting equipment.
