Ichthyological terms, not general ones.
Sand originating from marine environments via bioerosion of the calcareous skeletal structures possessed by some organisms. Coral is not the chief constituent, however, with the majority of material deriving from foraminifera, calcareous algae, molluscs, and crustaceans.
Used in 6 profiles
Naturally-occurring, crsytalline form of calcium carbonate with a notable buffering capacity. Popular as a substrate or substrate additive in marine and freshwater aquaria where pH and hardness must be maintained at high levels, and has a more rapid, effective effect than coral sand, for example.