Key Features BiOrb Maintenance Kit Consists of 3 x Service cartridges Also contains a bottle of Water Optimiser to help improve filtration Easy to use Suitable for all BiOrb The Oase biOrb Service Kit x3 set is a handy pack to help maintain your tank. The set consists of 3 maintenance service kits and a bottle of Water Optimiser Service Kit The filter cartridge in your biOrb should be changed on a regular basis. It is recommended to do this every 6 -8 weeks. The biOrb Service Kit contains a single replacement filter cartridge in its holder, a cleaning pad, 5ml of Water Conditioner and 5m of Biological Booster. All you could need to perform those changes with ease. Water Optimiser The Water Optimiser improves the biological filtration, removes impurities from the water and benefits the overall well being of your fish. Add a few squirts to your aquarium every week to help keep your tank water crystal clear and healthy. The spray is suitable for all aquariums and is 100% natural and