Corner Box Filter

This type of filter sits perfectly in the corner of a small aquarium. 

Shown in the photograph below is a triangular model with a rounded end that faces out from the corner. The back edges are at right angles and fit into the corner of the aquarium.

Box filters are more commonly available with four flat sides as would be expected from a typical box shape.

The box filter in the illustration includes a baffle at the bottom to help anchor it in your aquarium gravel. This is a handy feature but is not required for correct functioning. Some fish keepers will place a payer of marbles or pebbles in their box filter to achieve the same effect.

When the filter has been packed with polyester fiber and charcoal it will require a period of maturation before providing a full range of filtration methods. Once cycled a box filter provides chemical, biological and mechanical filtration.

This style of aquarium filter usually ships complete with an air stone which is positioned in the air uplift. While an air stone is not a necessity it will help to  produce a more consistent bubble flow with reduced filter movement and bubble noise.

Filter mediums or sponges may be included. Usually these filters are stuffed with a layer of polyester filter wool over an optional layer of carbon.

A box filter requires an air pump and airline for operation.

The small unit shown in the photograph measures 15 cm in height x 6 cm wide. Large size box filter will be more efficient and are usually a better choice. These may measure 17 cm in height x 9 cm wide or larger.