Internal filters for aquariums

Internal

— filters installed inside the aquarium. The vast majority are designed to clean small to medium volumes of water. Water is typically drawn in from the bottom of the filter, then it passes through a filtering element (foam or synthetic cotton) and is released from the top of the filter. The outgoing stream is directed toward the water surface, effectively enriching it with oxygen. These filters are often secured to the inner glass using special hooks or suction cups.