Reverse osmosis water is slightly acidic with a pH of 5 to 6.5. This is mainly because although the RO membrane filters out most contaminants, it’s unable to eliminate carbon dioxide.
After passing through the filter, carbon dioxide dissolves in the water, making it slightly acidic.
When carbon dioxide dissolves in the water, instead of adding extra H+, it removes the OH- ions by combining with the OH- to form HCO3-. This results in lower pH levels.
The more pure the RO water is, the more acidic it’ll get when it combines with carbon dioxide.
This sounds like complicated jargon, right? We simplify everything for you here by explaining what pH actually is. You’ll also learn how to increase the PH of RO water and more.
What's in this Guide?
What is pH?
pH stands for potenz hydrogen or, in simpler terms, the number of hydrogen ions (H+) present in a solution.
Water is an equal combination of hydrogen (H+) ions and hydroxide (OH-) ions.
If the number of hydrogen and hydroxide ions remains equal, the pH of the solution in question will be 7 or neutral.
Should the hydrogen ions start increasing, the pH of the solution will start ticking down, meaning that the solution is getting acidic.
If the concentration of the hydrogen ions increases, the PH of the solution starts ticking up, indicating that the solution is becoming more alkaline.
To measure the pH level of a solution, all you need is a pH meter.
Why is my RO Water pH so Low?
As effective as reverse osmosis is at removing contaminants from water, it has a major drawback – It removes alkaline minerals from the water, making it more acidic.
Some of the alkalizing minerals removed include calcium, potassium, and magnesium. Adding the minerals back to your water will not only raise the PH but also make the water healthier.
How Can You Increase the PH of RO Water?
- Add Baking Soda
If your RO water is too acidic for your comfort, you can add a small quantity of baking soda and mix it in to raise the PH.
Ensure that it’s just a tiny amount since you don’t want it to become too alkaline.
- Add a Remineralizing Filter
Adding a remineralizing/alkaline filter to your RO system will add some minerals back into the RO water. This will raise the pH closer to neutral and make your water taste better.
Adding a remineralization stage to your RO system is a long-term investment and requires less maintenance.
With a remineralizing filter in place, you won’t have to worry about low pH levels in your RO water.
- Alkaline Water Pitcher
An alkaline water pitcher works on the same principle as the remineralization filter. It adds minerals into the water to increase the pH level.
The only difference between a water pitcher and remineralization is that you can control the amount of water you want to neutralize when using a water pitcher.
- Add Himalayan Pink Salt
Himalayan pink salt is a natural salt that contains the necessary trace minerals removed during reverse osmosis. Adding a little salt to your RO water will help increase the PH level.
Q: What Should be the pH of RO Water?
Reverse osmosis water should have a pH of between 6.0 and 6.5. It should be slightly more acidic than pure water, which has a pH of 7.
Q: Will Reverse Osmosis Lower PH?
Definitely. Reverse osmosis lowers the pH of RO water by filtering alkaline minerals. The process makes the water slightly acidic.
The increase in acidity in the water is minimal and will not affect your health. This is because your body controls internal pH level well regardless of what you consume.
Q: Do Water Filters Increase PH?
If the filters remove salts and minerals from the water, they will definitely increase the pH level. However, you can lower the pH by adding the minerals back into the water through remineralization.
Increasing the pH of RO water makes it healthy and great-tasting. With a remineralization filter or an alkaline water pitcher, raising the pH levels of the water becomes very easy.
You can also add specks of baking soda in the water or natural mineral salt(source). Do not use common table salt as it can make the water too alkaline for your liking.