Organic Crab Shell Fertilizer, 2-3-0 Formula, 4-Lbs.Neptune's harvest, 4 lb, 2 3 0, organic crab shell, n excellent dry organic source of nutrients, including calcium 23% & magnesium 1. 33%, retains moisture in the soil & builds the organic matter & gives the roots something to grab onto & wrap around, for a food source, creating a deeper root system, high in chitin, kite en, which promotes the growth of chitin eating bacteria in the soil, will help eliminate ants, grubs, fungus & root nematodes & will