Alkalinity, or more commonly referred to as, carbonate hardness is a term that is often thrown around, but what does it mean?

We know we need to test for it. We know corals need it to grow. But what is it, and why is it important?

For the purpose of this brochure we will define alkalinity as this: Alkalinity is a measure of the acid neutralizing capacity of water. Acid neutralizing capacity means the ability to accept acid without a subsequent drop in pH. Alkalinity is basically a measure of how much antacid is dissolved in the water. The more acid that can be added to water before the pH starts to drop, the higher the alkalinity.