Pearl Beach™ Aragonite is an all natural substrate for all types of marine, reef and tropical aquaria. Simply rinse before use to remove any residual dust. To determine the number of bags required for your aquarium, please note that each bag (10 kg, 22 lbs) occupies a volume of 6500 cm3 (0.23 cu. ft.). To determine your desired volume multiply tank width by length by desired depth. Why should one use aragonite? Aragonite is a naturally occurring, calcium carbonate mineral. It is precipitated from ocean surface waters mainly by organisms (e.g., coral) that use it to make their shells and skeletons. In recent years, aragonite has nearly eclipsed all other marine substrates. This is chiefly because of it superior buffering capacity. Aragonite becomes soluble at a pH of 8.2. At this pH, the release of calcium and carbonates into the aquarium causes an upward shift in pH. This occurs so slowly, however, that aragonite is less of a viable buffer and more of a safety net. With aragonite in the aquarium, one can be reasonably sure, that the pH of the system will never go below 7.7-7.9. Additionally, aragonite's porous structure and size make it ideal for the propagation of denitrifying bacteria.