We offer two types of mud that is living. It is living because it contains microfauna that is alive. It also contains minerals and nutrients that plants need to thrive. Our Live Mineral Mud is usually black or very dark, fine, and smelly (this is a good thing). The mud that we obtain from the Keys is both fine and gritty due to various stages of decomposition. In addition to grasses, the Keys' mud also grew calciferous plants (such as halimeda). So, this mud would be beneficial to help coral that you might have in addition to plants.