Aquarium External Filters
These work on the same principle as internal power filters, but are positioned outside the fish tank & draw water into the filter through an inlet tube & return the water via another tube, which can be fitted with a spray bar to increase aeration.
They avoid the need for an unsightly filter inside the tank. The media capacity is much larger than internal filters and they are therefore suitable for much larger tanks. They normally incorporate areas for several media types so the media can be tailored to suit the requirements of individual tanks. They are a good choice for larger planted tanks.