A drive system for driving a mixer impeller shaft in a vessel, including a motor; an outer magnet rotor driven by the motor; a bearing housing mountable to a vessel; and a drive shaft rotatable in the bearing housing. An inner magnet rotor is connected to the drive shaft and a manifold plate is connected to the bearing housing. A canister is connected to the manifold plate so that a chamber is defined in the bearing housing having an inlet port for directing fluids into the chamber. A plurality of ports extend through the manifold plate providing fluid communication from the chamber to the inside of the canister; and a plurality of ports through the inner magnet rotor provide fluid communication from the inside of the canister through the inner magnet rotor. A fluid path is provided from the chamber through the ports, around the inner magnet motor, and through the inner magnet rotor, which fluid path is sealed from the environment by the canister.