In a pond filter, loose media (bio-balls, ceramic, zeolite, charcoal) scatter, clog passages, or are difficult to remove for cleaning. A mesh bag holds them in place, allowing you to rinse and replace them without emptying the entire compartment.
Aquaforte bags with drawstring, from 45 x 30 cm to 85 x 50 cm, in black, red, or yellow depending on the mesh size.
Superfish filter media bags, from 15 x 25 cm to 50 x 85 cm, in fine or coarse mesh.
Superfish super activated carbon in a 10-liter bag.
Choose the size of the bag according to your filter compartment, leaving room for water to circulate through the media. The mesh must be finer than the grains being contained: fine mesh for small grain sizes, coarse mesh for larger media.