NPX Bioplastics NPX Bioplastics granular media made from biodegradable polymers. For use in a fluidized reactor. The slow release of organic food from these plastics promotes the development of bacteria that assimilate nitrate and phosphate. These bacteria can be harvested by protein skimmers, so that the nitrate and phosphate levels are naturally reduced. The bacteria are also a food source for filter-feeding invertebrates such as corals, clams, sponges, and feather dusters. Use with Bactiv8 NPX to promote rapid assimilation of nitrate in saltwater aquariums.