Well proven pumping solution that has been delivered for decades.
The vacuum system can be delivered in a number of different configuration, the most common tank sizes is listed below
The vacuum pressure unit (VPU) evacuates air from the tank, which allows the tank to be filled. In its next cycle it will pressurize the tank moving the medium into the flap valve unit. The flap valve unit is designed to ensure that fish will not be damaged by the flap closing