No, reverse osmosis (RO) water is not inherently alkaline. In fact, it's typically neutral to slightly acidic.
Understanding RO Water and pH
Reverse osmosis filters remove almost all minerals and impurities from water, resulting in pure H₂O. This process often leads to a pH level around 7 or slightly lower, meaning it's neutral or slightly acidic, not alkaline (pH > 7). As noted, "Within about an hour, a glass of pure RO water can drop from a pH of 7 down to a pH of 5.5 or lower and become acidic water. Alkaline water has a pH of greater than 7, so reverse osmosis water is not alkaline water."
Several sources confirm this: a Reddit thread on water treatment shows that RO water measured 6.0 pH before remineralization. Another source mentions that RO water is "slightly more acidic than pure water, which has a pH level of around 7 – 7.5". Similarly, an article states that RO water "typically has a neutral to slightly acidic pH, generally around 7 or below".
Alkalizing RO Water
To make RO water alkaline, you need to add minerals like calcium and magnesium. Many alkaline RO systems achieve this through a multi-stage filtration process that includes remineralization filters. These filters add back essential minerals lost during the RO process, raising the pH to an alkaline level.
- Example: Express Water's Alkaline RO System utilizes a multi-stage filtration process to deliver purified, alkaline water. Other brands, such as iSpring, also offer alkaline RO systems with remineralization.
The addition of minerals not only increases the pH but can also improve the taste of RO water, making it more palatable for many.
