In order to ensure the smooth running of any fish tank filter, it needs to include filter media so that any dirt and waste removed from the aquarium doesn't go straight back into the tank or continue to pollute the water. New filter media is added to media bags which are then placed in the fish tank. Media bags themselves also have a role in the filtering process.
Seachem The Bag filter bags are made from 180 micron mesh that offers a very fine and durable bag which is resistant to bleach, caustics, and acids and comes with a convenient resealable locking closure to ensure that the filter media will not escape. Swell has a wide range of filter media, of all types; mechanical, biological and chemical.