CaribSea Samurai Soil is a unique uniformly graded material that fits the pH and mineral requirements of the most sensitive freshwater fauna and flora without the muddy texture and crumbling often seen with other brands. A complete substrate eco-system is infused with mycorrhizal fungi for enhanced root development and each package contains a dose of biologicals for a faster and more thorough cycle. Ideal substrate for shrimp and planted aquaria. Cleaned and ready to use Promotes neutral to acidic pH Contains a dose of biologicals for a faster and more thorough cycle Will not disintegrate or compact Will not increase hardness