Aquarium Undergravel Filter BOYU Fish Tank 17"-47" x 12" UF-12P to 32P - 6 Sizes
Aquarium Fish Tank Undergravel Filter Boyu 17"-47" x 12" UF-12P to 32P - 6 Sizes. How does an undergravel filtration system work?. The filter system is run using either a traditional air pump or power-head water pump.