Determination of adsorption efficiencies of activated carbon from pericarp of rubber fruit for calcium (II) ion and iron (II) ion has been performed by flowing the solutions of these ions through a column of activated carbon. The weights of activated carbon in 500 mL buret column (diameter 3. 2 cm) for flowing calcium (II) ion and iron (II) ion solutions were 15 g and 10 g. respectively. https://www.unitedssports.shop/product-category/hockey-accessories-home-sharpening-machines/