Kent Marine Biosediment is a blend of aragonite, calcite, and other minerals; it is not any mere aragonite substrate.  Marine Biosediment has been formulated in ratios that not only provide a much more natural substrate composition and density than using plain aragonite alone, but also to slowly dissolve as a result of natural solubility and close-proximity bacterial respiration, simulating the processes at work in sediment found on reefs, in lagoons and sea grass beds, and around mangroves.  Rather than being a blend of terrigenous (terrestrial in initial origin, i.e. silica sand, humus, etc.) particles, Marine Biosediment is composed of minerals naturally occurring in the afore-mentioned marine habitats, and therefore brings the aspiring hobbyist one step closer to providing his/her aquarium inhabitants a truly representative piece of the ocean. Over time, Marine Biosediment slowly releases trace amounts of calcium and other elements due to microbial processes taking place below the surface of the substrate; again, this simulates natural cycles taking place in benthic marine ecosystems.