Maintaining a marine aquarium is a little more involved than a freshwater aquarium so the right equipment is imperativer this service kit makes it as simple as possible by supplying everything you need in one kitr the kit contains a replacement filter cartridge which is specifically for marine biorb the biorb standard service kit should not be used in marine biorb as it contains a different mix of chemicalsr a measured amount of high quality reef grade salt and water preparation chemicals a