Water that contains high amount of Mg and Ca metal is hard water. The present of these metal ions in water prevent the water from lather formation with soap. This leads the consumption of large amount of soaps which cause loss of economy. In light these facing in problem; this study is conducted to investigate the capability of cactus powder to remove Mg and Ca metal from hard water using FAAS. As the result revealed that the Concentration of both Mg and Ca metal are decreased as the dose of cactus powder increased. The Concentration of Mg was 5.965ppm in the absent of cactus powder, but it is 6.700ppm at 0.5g, 2.967ppm at 1.5g, 1.833ppm at 2.5g, 2.200ppm at 3.5g and 1.900ppm at  4.5g  of cactus powder. In parallel way, the Concentration of Ca was 4.967ppm in the absent of cactus powder, but it decreased as 3.067ppm at 0.5g, 1.667ppm at 1.5g, 0.933ppm at 2.5g, 0.967ppm at 3.5g and 1.033ppm at  4.5g with cactus powder. The percentage removal of both Mg and Ca metal from hard water increased as the dose of cactus powder increased. The percentage removal efficiency of cactus powder increased from 0.00% to 68.2% for Mg metal, and from 0.00% to 79.2% for Ca metal as the dose of cactus powder increased from 0.0g to 4.5g, respectively. The percentage removal of Ca metal increased with contact the period of time as 27.89% at 1hr, 38.69% at 2hr, 53.27% at 3hr, 71.11% at 4hr and 71.53% at 5 hr. In the same way, the percentage removal of Mg metal increased with contact time as 16.00% at 1hr, 32.84% at 2hr, 48.00% at 3hr, 61.00% at 4hr and 57.00% at 5 hr. Thus, cactus powder has the capability to remove Ca and Mg metal ions from hard water due to the accessibility of its active sites.

Keywords: Cactus Powder, Hard Water, Magnesium and Calcium Metal