The Fountain Cube C is a water-quality module designed specifically for the PETKIT EVERSWEET ULTRA pet water fountain. It sits at the fountain's water outlet and must remain installed at all times to maintain consistent water quality. Its high-density sintered activated carbon core forces every drop of water through a solid carbon wall, eliminating bypass and residue for pure, fresh-tasting water that pets naturally prefer. The Fountain Cube C also slows slime buildup in the water tank by 30 percent, keeping surfaces cleaner for longer and significantly reducing fountain cleaning. Replacement is tool-free: simply pull out the old cube and push in the new one, with no disassembly and no mess. It delivers consistent, high-performance filtration for up to 30 days, and the PETKIT app tracks the module's lifespan in real time with automatic replacement reminders. With high-density activated carbon, reduced slime buildup, and a tool-free swap, the Fountain Cube C keeps the EVERSWEET ULTRA's water consistently fresh and neutral-tasting while making monthly maintenance simple.