Reverse osmosis (RO) water typically has a pH range of 6.0 to 6.5.
Understanding the pH of RO Water
The pH scale measures how acidic or alkaline water is, ranging from 0 (highly acidic) to 14 (highly alkaline), with 7 being neutral. Reverse osmosis is a water purification process that removes most dissolved solids, minerals, and impurities from water. While tap water often has a neutral or slightly alkaline pH (usually between 7 and 8.5) due to dissolved minerals, the removal of these minerals during the RO process can result in water that is slightly acidic.
According to information dated September 13, 2021, the water produced by reverse osmosis systems generally falls within a pH range of 6.0 to 6.5. This makes it slightly acidic compared to perfectly neutral water (pH 7.0).
RO Water Compared to Other Drinks
The reference also notes that various common beverages are more acidic than RO water. Drinks like:
- Tea
- Coffee
- Carbonated drinks
- Fruit juices
These beverages have lower alkalinity than reverse osmosis water, meaning they have a lower pH value and are therefore more acidic.
Factors Affecting RO Water pH
While 6.0-6.5 is a common range, the exact pH of RO water can sometimes be influenced by:
- Source Water pH: The pH of the incoming water can have a minor effect.
- System Efficiency: How effectively minerals and dissolved gases (like carbon dioxide) are removed. Dissolved CO2 can make water slightly more acidic by forming carbonic acid.
- Post-Treatment: Some RO systems include a remineralization stage which adds beneficial minerals back, potentially raising the pH closer to neutral or slightly alkaline.
Knowing the typical pH helps understand the characteristics of water purified by reverse osmosis for various uses, from drinking to specific industrial applications.
