Abstract: A magnetically operated fan device includes a fan member rotatably supported on a housing, one or more magnetic members disposed in the housing, a base supported in the housing, a follower rotatably attached to the base and having a frame, an axle rotatably attached to the frame and having one or more eccentric members for increasing moment of inertia of the axle, one or more magnetic members attached to the eccentric member for acting with the magnetic members of the housing, to bias the axle to continuously rotate relative to the frame of the follower. A coupling device may couple the axle to the fan member, to have the fan member to be driven continuously by the magnetic members and the eccentric members.

Abstract: An aquarium includes a pump disposed in a chamber of a container to circulate water and having a spindle. An air supplying device is coupled to the spindle of the pump and driven by the spindle of the pump, to pump air into the water contained in the chamber of the container. The pump may thus be used to pump or circulate the water in the aquarium, and to simultaneously supply air into the water contained in the aquarium. The air supplying device includes a valve housing having two check valve members disposed in a recess and a depression, and a membrane attached to the valve housing and forced by the pump to actuate the check valve members.

Abstract: An aquarium having a powerless air pumping device includes a cycle filter device, and an air pumping device. The cycle filter device includes a water pumping pipe connecting with the air pumping device, so that the motor and the water pumping pipe of the cycle filter device may pump the water contained in the aquarium into the air pumping device, to serve as the power source of the powerless air pumping device.