Information about KH, also known as… alkalinity, buffering capacity, and carbonate hardness.
KH – Buffering Capacity
KH is the solution’s ability to maintain a stable pH when an acid (H+ ions) is added. Therefore, it can also be described as a measure of the solution’s composition of bicarbonate (HCO3–), carbonate (CO32-) and hydroxyl (OH–) ions; as these ions readily react with added H+ ions and prevent them from decreasing the pH value.
Different species of shrimp can adapt to different ranges of KH, corresponding with the KH of their natural environment. It is therefore important to provide a suitable KH for the species in order to have healthy shrimp. Water with lower KH values are generally more susceptible to pH fluctations. The need to provide a stable pH often conflicts with the KH of the shrimp’s natural environment, and so a compromise must be established. Of course, the shrimp will naturally occur in water where the sheer volume prevents any significant pH changes. As aquaria have far smaller volumes of water, pH fluctuations can become a problem.