[Pack of 4] - Marina Power Cartridge Replacement for i25 Internal Filter i25 Filter Replacement Cartridge

• Replacement Power Cartridges for Marina i25 internal filter
• 3-in-1 mechanical, chemical and biological filtration
• Ideal for goldfish and tropical tanks

Each cartridge is split into two separate chambers: the first chamber contains zeolite to remove toxic ammonia, and the second chamber is the activated carbon chamber so that pollutants and odors get removed. The water finally enters the floss layer, where the debris gets trapped inside the cartridge. This helps keep your aquarium water crystal clear! For best results, replace cartridge every 4 weeks.