Aquarium

An aquarium comprising:

• a bottom tank which has a pump provided therein so that water in the bottom tank is able to be pumped upward to the top tank via a first pipe and water flowing out of the first pipe and splashing into the top tank is able to increase aeration of the water in the top tank, the bottom tank has a first drainage pipe provided on top of the bottom tank to maintain a water level in the bottom tank at a predetermined level;
• a middle tank which is mounted on top of the bottom tank and has an opening defined in a bottom plate of the middle tank, a filtering box mounted on top of the opening to block the opening, a collecting pipe mounted on top of the filtering box and having an inlet defined away from the filtering box, a receiving box mounted on an outer periphery of the collecting pipe and having a second pipe extending out of the middle tank, a lid mounted on top of the collecting pipe to cover the inlet of the collecting pipe and a funnel in communication with the lid via a conduit having a valve mounted therein to control the communication between the funnel and the lid;
• a top tank which is provided with a bottom having a through hole defined therethrough, a filtering plate mounted on top of the bottom to cover the through hole and having multiple apertures defined through the filtering plate, a top board mounted on top of the top tank to cover the top tank, an illuminating device to illuminate the top tank and a feeding device mounted on top of the top board for distributing food to fish in the top tank.