A.R.M. is processed for immediate use, no rinsing required, and has double the surface area of regular aragonite. Precision grading (10-15 mm) allows for maximum carbon dioxide penetration, and the exclusion of gastropod shells insures the lowest phosphate (less than 1/10 of 1 ppm) and silica (about 1/2 that of other brands) content. This grading also carries in the highest concentration of Halimeda incrassata, an aragonite so pure it has been used as a laboratory standard.