Alkalinity refers to the amount and types of chemical compounds that can
shift the pH toward the higher side of neutrality. Alkalinity is usually
measured by the presence of bicarbonate (HCO3-) and
carbonates (CO3=)and acts to buffer lakes
from acidic inputs, thus is a measure of the buffering capacity of a lake.
Lakes with high alkalinity have high pH values while lakes with low alkalinity
have low pH values. The hardness of the water is usually determined by
the amount of calcium and magnesium salts present in water and is associated
with the presence of carbonates. Hard water lakes are generally more productive
than soft water lakes and can accept more input of salts, nutrients, and
acids to their system without change than can soft water lakes.
