Definitions for "Undergravel Filter"
a device for enhancing bacterial nitrification in substrate, made of a slotted plate which is placed under the substrate.
This type of filter involves a few long, plastic tubes which remain upright in the aquarium and are attached to a plate on the bottom. In each tube is an air stone attached to an air pump. As the air bubbles rise, a current is generated which continuously brings water from the aquarium, through the substrate and to the top of the tubes.
a perforated plate that is under the gravel in the tank, connected to a pump
Keywords:  ugf, see
(see UGF)