Oyster Shell Flour

Heavy Metals (PPM)

Arsenic       <0.5

Cadmium     <0.50

Mercury        <0.05

Lead         <5.0

Nickel         <1.0


Source:   Data From Oregon Department of             Ag Organic Certification Database

Oyster shell flour is a slow but effective pH-increasing product that contributes calcium and micronutrients as it mineralizes.

Oyster shell is a great product to use in conjunction with ag lime when raising the pH. Ag lime does the job quickly, while oyster shell provides a long-lasting pH buffer in the soil.

Oyster shell is somewhat elevated in sodium and chloride, reflecting its oceanic origins. Therefore, using it in moderation is suggested.