Only CaribSea\'s Aragalive contains not just the broad spectrum of natural marine bacteria found in the ocean, but additional specifically selected strains of marine bacteria aswell. Aragalive helps control dangerous ammonia levels and reduces nitrate and nitrite. Aragalive creates a natural biological balance, and makes cycling a new aquarium safer and faster. Available in six different environments for use in all marine and reef tanks including Plenums, nitrate reduction beds, sumps, fish tanks and more! The entire Caribsea range comes highly recommended by everyone at the Warehouse Aquatics team. Suitable for use in marine aquariums.This substrate is not suitable for freshwater aquariums.