(black, 10-30 cm (10 kg)) vidaXL Volcanic Rocks Lava Accent Rocks Aquarium Volcanic Lava Stones Beads

【Decorative Element】: Features a unique natural shape and black colour to add visual appeal to your fish tank or aquarium 【Biological Filtration】: Serves as an effective biological filter in aquariums, promoting better water quality, improved oxygen levels, and controlled nitrate levels 【Versatile Usage】: Apart from aquariums, these black volcanic rocks can be used in garden landscapes, planter beds or any other rock applications 【Large Quantity】: Pack contains sizable 10 kg of volcanic rocks, providing a considerable amount for aquariums and landscaping purposes 【Natural Material】: Made from 100% natural volcanic rocks, ensuring no alteration to aquarium water pH or chemistry