Pro Series Buffer 8.3™ Pro Series Buffer 8.3™ raises and maintains pH to 8.3 is a solution that contains a balanced blend of bicarbonate, carbonate and borate salts. It is designed to adjust the pH between 8.0 to 8.3 and raise alkalinity or carbonate hardness (KH). Alkalinity is important for maintaining a high pH. Pro Series Buffer 8.3™ is also essential for coral growth when used with our calcium additives. A wide variety of invertebrates in reef aquarium including corals, mollusks and algae absorb calcium and carbonate from the water for protection, body support and calcification.