The ARM Extra Coarse is a high magnesium reactor and still a complete reactor media containing not only calcium and carbonate but essential trace elements as well.
Caribsea ARM Extra Coarse is the largest size granules and the least likely to clog equipment which results in the lowest maintenance option.
A.R.M. is processed for immediate use, no rinsing required and has double the surface area of regular aragonite.
ARM Extra Coarse contains:
Precision grading (2-3 mm) allows for maximum carbon dioxide penetration, and the exclusion of gastropod shells ensures 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.
ARM has the highest solubility of any reactor media available (metastable at 8.2) so CO2 consumption is much lower.