Letter Grade 4.0 Point Scale (+/-) A+: 4.0: A: 4.0: A-3.7: B+: 3.3: B: 3.0: B-2.7: C+: 2.3: C: 2.0: C-1.7: D+: 1.3: D: 1.0: D-0.7: F: 0.0
Coral calcium is a salt of calcium derived from fossilized coral reefs (primarily from limestone and coastal deposits).It has been promoted as an alternative, but unsubstantiated, treatment or cure for a number of health conditions.oral calcium is a source of calcium, which is an essential mineral for human life. Coral has a chemical structure that is very similar to the composition of human bone and is sometimes used as material in bone grafts.
It appeared my corals were missing calcium as the would just fall apart, but the Hanna calcium checker kept reading over the normal value (high). I had my water tested with triton and it showed very low calcium.