CaribSea Black River Pebbles (25 lb) – Smooth, round natural river pebbles in dark tones, ideal for decorating aquariums, terrariums, or water gardens. These polished black stones come in assorted sizes and provide a realistic stream or riverbank look when used as substrate or accents. They are completely inert and won’t affect water quality, making them suitable for freshwater tanks (great for goldfish, cichlids, etc.). Whether used to edge a pond, scatter on a tank floor, or create zen-like rock arrangements, Black River Pebbles add an elegant, natural touch to any aquatic environment.