Coastal Aquaculture and Mariculture (2+1)

Unit 4 - Water and soil quality management

4.1.2.b. Total alkalinity

• Total alkalinity is the total amount of titratable bases in water expressed as mg/L of equivalent calcium carbonate.
• The principal ions that contribute to alkalinity are carbonate and bicarbonate and, to a lesser degree, hydroxides, ammonium, borate, silicates and phosphates.
• Alkalinity is a measure of pH buffering capacity or acid neutralizing capacity.
• Natural seawaters have a mean total alkalinity of about 116 mg/L. Generally speaking alkalinity below 30 mg/L is considered poorly buffered against pH changes. Thus in brackish waters and sea water alkalinity is rarely of concern.