A truly innovative filtration system designed for simplicity and convenience. From its innovative use of Timestrip® technology to the new patented carbon filter carrier, every new feature has been designed with simplicity and convenience in mind. This is the intuitive filtration system. "Simple Set Up -- Ready to go right out of the box. No priming required due to pump sitting inside the tank. "Simple Operation -- Patented Timestrip technology lets you see at a glance when its time to replace your carbon filter. "Scientifically Engineered Water Flow -- Continuous flushing action prevents debris build up. Outflow maximizes water agitation and oxygenation. Tetra FS Filtration Systems use Tetra carbon Cartridges . Timestrip Cartridge Change indicator included