FINE OYSTER SHELL If you are looking to add 'crunch' to your baits, here's the answer. This fine ground oyster shell can be added into mixes at around 10% to add texture, a 'flecked' appearance and weight to baits when distance is required with a throwing stick. Fine oystershell is also a valuable source of calcium. Can be included in base mixes at up to 2oz per lb.