For aquariums to 90 gallons. Sealed unit eliminates risk of water overflow and compact design allows filter to fit in most cabinet stands. Bi-directional water movement allows for more contact time between bacterial colonies, oxygen, and toxins, resulting in a more rapid breakdown than standard filters provide. Pumps 270 gallons per hour. Water return tube assures proper O2 and CO2 gas exchange. Water output pulsates as filter fills and empties, creating rhythmic currents inside your aquarium. No Drilling Required. Model 2227 - Provides over 14,000 square feet of surface area for bacterial colonization when using almost 5 liters of Ehifisubstrat. For aquariums to 90 gallons. Model 2229 - Provides over 22,000 square feet of surface area for bacterial colonization when using almost 6.4 liters of Ehifisubstrat. For aquariums to 160 gallons.
