180 Gallon Black w/2 overflows A super-efficient overflow aquarium system that combines a custom Perfecto aquarium with Marineland's advanced water-flow technology. Engineered to deliver perfect circulation and maximize water flow to the main filter system while minimizing flow noise, the Corner-Flo eliminates filtration dead zones. Water is drawn from the surface and bottom levels at an unprecedented rate of up to 700 GPH, providing the ultimate in circulation efficiency...and fish keeping success. Silicone sealed to the back corner walls of each aquarium, the Corner-Flo keeps all Corner-Flo components protected and out of sight. The front section is removable for easy, convenient cleaning.