When pH is not an issue, Reef Builder™ or Reef Carbonate™ should be your first choice for a carbonate alkalinity supplement.
Reef Buffer™ is specifically designed to meet the needs and requirements of the closed reef environment. The principal difference between Reef Buffer™ and Marine Buffer™ is that the pK of Reef Buffer™ is slightly higher than that of Marine Buffer™. The pK of a buffering agent is equivalent to the pH around which that buffer most strongly buffers. One would presume, then, that the pK of a saltwater buffer should be 8.3; however, the multitude of organic acids produced by the inhabitants of a reef system forces pH downward to a much greater degree than in a non-reef, marine system. A buffer with a pK of 8.3 would end up yielding a pH more in the range of 8.0-8.2. Reef Buffer's ™ higher pK (8.6) allows for greater pH stability in a reef system where the bioload is significantly more than in a fish only system.