A.R.M. Calcium Reactor Media is a complete reactor media containing not only calcium and carbonate, but essential trace elements as well. A.R.M. is processed for immediate use, no rinsing required, and has double the surface area of regular aragonite. Precision grading (2-3mm) 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. Size: 1 gallon
