Fluval Plant Stratum is the ideal substrate for planted aquariums featuring a light non compacting porous structure, Its ideal properties as an aquarium substrate are highly beneficial to nitrifying bacteria which rapidly colonize the vast porous surface, providing optimal water quality for fish, Plant roots easily penetrate and spread within the Fluval Plant Stratum allowing plants to flourish and obtain a variety of key nutrients, The inherent properties of Fluval Plant Stratum will help support a neutral to slightly acidic pH, ideal for most plant species and species of tropical fish normally kept in planted aquariums, This highly attractive substrate does not discolor water, and helps control organic discoloration usually present when natural driftwood is used, The Fluval Plant Stratum Features and Benefits:, - Freshwater use only, - Made of a light non-compacting porous structure, - Supports a slightly acidic pH, ideal for most plant species and tropical fish kept in planted aquariums, - Helps plant retrieve a variety of key nutrients, - Does not discolor water, and helps control organic discoloration usually present when natural driftwood is used, - Recommended depth is 1, 25"" to 1, 5"", - For aquariums less than 18"" use one 4, 4 pound bag of Stratum; 18"" aquariums require one 8, 8 pound bag of Stratum; 24"" aquariums require two 8, 8 pound bags and 35"" aquariums require two 8, 8 pound bags, SKU: RCHG0182