LANDEN Aquarium Mekong Sand The brownish-black Mekong sand is a darker-colored, rougher textured sand, usually used for aquascaping in aquariums, and is suitable as natural sand for general aquarium substrate or aquascape layout makeup sand. It is ideal for a native aquascape type of aquarium environment. It can be used with dark-colored plants, rocks, wood, etc., to form a natural and realistic environment. The brown-black Mekong sand also allows fish and other aquatic organisms to hide in the water, better simulating their natural habitat. It can be used in various landscaping styles, such as black water landscaping, tropical rainforest landscaping, etc. Medium-grained Mekong sand of 2-5mm can create natural riverbeds and simulate underwater environments. It has a moderate settling speed, does not readily disperse, and provides a suitable growth environment for benthic organisms.