Oyster Shell Flour
Crushed oyster shells used as a source of calcium carbonate and soil conditioner.
What is it ?
Oyster shell flour is crushed oyster shells containing a high amount of calcium carbonate which will release a steady amount into the soil. It also contains a small amount of phosphoric acid. This additive can buffer pH by increasing its level over time and a mixture of particle sizes facilitates both rapid and slow-release of these nutrients.