Safe & Non-Toxic (Small Size, 0.25″ Inch) 50 Pound Bag of Gravel & Pebbles Decor for Freshwater & Saltwater Aquarium w/ Dark Rugged Natural Seafloor Pond Style [Gray, Brown, Tan & White]

SIZE OF SUBSTRATE: Substrates vary widely in terms of size - everything from sands consisting of very tiny particles to larger river rocks. Large particle substrates allow more uneaten food and waste to penetrate into it leading to toxic build ups...