Petco White Aquarium SandPetco aquarium sand is ideal for freshwater, and safe for marine aquariums. The sand is processed to remove potentially harmful debris and metals, and assists in breaking down waste. It will not affect the water"s chemistry, nor harm any aquatic life (fish, invertebrates, or plants). By combining sand, plants, and decor, which provide cover and hiding places, you will create a healthy environment for your fish.