Angels Aquatics & Pet Supplies Hexagon Aquarium Fish Tank Under Gravel Filter Medium Hexagon 12.5" x 7"

Hexagon Under Gravel Filter 12.5" x 7" For Aquarium Size 13.5" x 8" Filter is 12.5" from corner to corner and 7" on each side comes with 1 uplift tube, air line and 1" air stone strong plastic constuction air pump required (not included) (spare uplift tubes are available) The Filter is placed on the inside base of the aquarium with the uplift tube attached to one corner of the filter plate, the filter plate is then covered with gravel (or other substrate) the air stone is the connected to the air line and fed down the uplift tube the other end of the air line is then connected to your air pump it is always best to have a none return valve in place about 6" from the air pump to prevent any back flow of water getting into your air pump.