Neptune's Harvest Organic Crab & Lobster Shell is an excellent dry organic source of nutrients, including Calcium (17%) and Magnesium (1%). It retains moisture in the soil and builds the organic matter. It also gives the roots something to grab onto and wrap around, for a food source, creating a deeper root system. Crab & Lobster Shell is high in Chitin (Kite-en), which promotes the growth of Chitin eating bacteria in the soil. It will help eliminate Ants, Grubs, Fungus and Root Nematodes, because they are all Chitin based in structure. Put around plants, Crab & Lobster Shell will keep slugs and snails off. It also helps choke out weeds and keeps critters from digging up plants. Work into the soil before planting, for best results. This Crab and Lobster Shell comes from cold, clean, dark, mineral rich North Atlantic Ocean water, off the coast of New England.