Micron Bag 4 Inch 200 Micron. Ensure crystal-clear water in your aquarium or pond with this Micron Bag 4 Inch 200 Micron. This high-quality aquarium filter bag provides superior mechanical filtration by trapping very fine particles, polishing your water to a brilliant shine. Designed for use in sumps or other filtration systems, the 200-micron mesh effectively removes debris, uneaten food, and other pollutants that can cloud your water. Its convenient 4-inch size and durable construction make it an essential tool for maintaining optimal water clarity and health. This filter bag is also reusable, providing a cost-effective solution for your filtration needs.