What Is Alkalinity?
The explanation on what exactly this is might be hard to grasp without a rudimentary understanding of pH itself. But, honestly, the term a junk one anyway. It’s neither helpful nor insightful on it’s own, GH, KH, and pH are all more helpful metrics. But, for the sake of explaining, here we go! Alkalinity is a term that’s used to describe your water’s ability to maintain a stable pH. This is not to be confused with alkaline water, which refers to the pH.
As a quick refresher; pH is the measurement of ion ratios. It’s comprised of two ion groups – acidic and base. More acid than base means it’s acidic, an equal amount of acid and base is neutral, and a low number of acid to a high number of base is alkaline. The higher number of base ions free in the water, the higher the pH, the lower the number, the lower the pH. Base ions have the ability to bind with acid ions and neutralize them – increasing your base to acid ratio – and thus, increasing your pH.
Back to alkalinity now. It refers to the water’s ability to neutralize acidic ions in the water, usually through bicarbonates, carbonates, and hydroxides – ie: certain base ions. These base ions create what is known as the “buffering” capacity of your water. The higher these base ions, the more stable the water’s pH will be, the higher the alkalinity. The lower the base ions, the less stable the pH becomes, and the lower your alkalinity.
It’s important to note that not all base ions impact your alkalinity (the KH or carbonate hardness.)
Examples of Alkalinity
Soda lakes such as, well, Soda Lake in Nevada, Lake Natron in Tanzania, and Lake Van in Turkey are all good examples of alkalinity at work. They all have high high concentrations of sodium bicarbonates (aka common household baking soda) and their pH is usually high as well as a result – typically between 9.0 – 12.0.