RUKDA Natural Lava Rock Gravel is a premium-quality volcanic stone designed for aquariums, plants, and decorative landscaping. Each 900gm pack contains naturally porous lava gravel sized 0.5–2 cm, ideal for biological filtration and excellent drainage. PERFECT AS AQUARIUM SUBSTRATE & SAND: > It supports beneficial bacteria growth, works beautifully as fish aquarium sand, and creates a healthy, natural environment for fish, shrimp, and aquatic plants. The porous gravel texture keeps substrate from compacting. ESSENTIAL FOR BONSAI, SUCCULENTS & TERRARIUMS: > Used as plant stones for pots, it improves airflow, prevents waterlogging, and promotes healthy root development. It makes an excellent top dressing or soil mix component for indoor plants, cactus, and terrariums. VERSATILE HOME & GARDEN DECOR: > These heat-resistant lava stones are also perfectly suited for BBQ grills and fire pit rocks base layers. Their natural black texture beautifully complements white stones, decorative pebbles, and vase fillers in home arrangements, zen gardens, and balcony planters. 100% natural, chemical-free, reusable, and long-lasting.