In water, pH is affected by both “gases” and “minerals”. The more mineral vs. gas, the higher the pH. We boost the pH one of two ways:
The first way is by adding a filter that introduces a small amount of calcium bicarbonate to the water. This calcium is the same type that one would find naturally in surface water or in well water. This type of filter will “boost” the pH of reverse osmosis water to an even 7 or neutral.
The second method is by using a filter which adds small amounts of Calcium, Magnesium, Potassium and Sodium. This will bring the water up to a pH of between 7.5 to 8.5.