Before I start discussing this I need to acknowledge that the information I write about has been the result of conversations with Robert Slovak and listening to lectures on this subject. Robert Slovak is a degreed Mechanical and Astronautical Engineer and a respected scientist. He has over 30 years of experience in the water treatment industry, specializing in membrane separation technology and products. Mr. Slovak has been featured on many health sites and blogs including Dr. Mercola.
I am going to become very unpopular with people who are selling water that is supposed to be of "high alkalinity." The term "alkaline water" means that the water has a pH that is greater than 7.0. That's it. Nothing more! Many companies are selling "Alkaline" filters and using pH meters to demonstrate that the alkalinity has been raised because the pH tests at 8.5, or 9.5 or even 10.5. They are confusing elevated pH with raised alkalinity. The fact is: THERE IS NO CONNECTION! Just raising the pH with an "alkaline filter" does not, in itself, raise the alkalinity. Water with high alkalinity may be beneficial in some circumstances to the body, but raising the pH serves no function whatsoever.
IT IS NOT ALKALINE WATER THAT YOU NEED, IT IS WATER WITH ALKALINITY!
So, if you are buying a filter for the purpose of substantially raising the alkalinity of the water you drink, you are most likely being duped by "junk or pseudo science." This is real science that I am speaking about - merely raising the pH does not raise the alkalinity. That's junk science.
The pH of water is not the indicator of it's capacity for neutralizing acid. Alkalinity is the indicator of the water's capacity to neutralize acid. Alkalinity measures the ability of a solution to neutralize acids - pH has no relation to that process. A water solution that is alkaline is not necessarily "alkalizing." Do not be duped into thinking "Alkaline pH" means that the water has significant alkalinity. Tests have shown that even the best "alkaline filters" raise the alkalinity only 30 to 35 mg/l which is insignificant. A half-tablespoon of Baking Soda add 1500 mg/l of alkalinity to the water at a pH of 8.4. Spinach juice has an alkalinity of 2250 mg/l but at a pH of 6.7. Like I said earlier, the pH has no correlation to alkalinity.
There is a great deal of mis-information out there about water treatment. Most people I have talked to who are promoting alkaline water have little to no understanding of this. If you want to alkalize your water, you don't add an alkaline filter - it is a waste of money and it does nothing. Here are the only ways that you can alkalize your water:
- Add 1/2 to 1 tablespoon of baking soda to a large glass of water;
- Consume foods and beverages rich in mineral alkalinity buffers, especially "green juices;"
- Add alkaline powders to the water.
There are a lot of misconceptions in the health-improvement industry about the pH and alkaline correlation. For instance, look at this popular chart:

That's a pretty impressive chart, but it's not correct. For example, they say lemon has a pH of 10 - it's really 2.69. They say the same thing about spinach, but it has a pH of 6.69. They also say RO water has a pH of between 4 and 5. In reality, it's usually about 6.5 or 6.6. Be careful of what you believe.
Here's what you need to know about alkaline water: if you are buying a filter to alkalize your water, you would be better served giving it to the Tooth Fairy. You can alkalize your water, but it has to be with one of the above methods. Simply raising the pH does not alkalize the water. Reverse osmosis continues to be the most economical and effective way to purify water and if you want to raise the pH and re-mineralize, then an alkaline-type filter is effective. At US Water Systems, we do sell a re-mineralization filter, right
HERE, but just not for the reason most companies say they are selling it.
The is the truth, the whole truth and nothing but the truth, so help me God.