Filter device for aquarium tanks or artificial ponds

An improved filtering device for an aquarium tank or an artificial pond mainly comprises:

• a water injector which is made up of a top cover plate and a water injector base;
• a multi-layered filtering member filled with filtering materials;
• and
• an external shield cup which is used to contain the filtering member;
• wherein:
• the top cover plate further comprises a water inlet switch unit and a water discharge switch unit for connection to the aquarium tank or artificial pond, a movable lid which is located on said top cover plate in a position above a motor housing, an air discharge valve in fluid communication with a first air discharge trough on the water injector base, a sealed motor chamber which forms with the top cover plate a one piece body which is located on the water injector base, attached to the sealed motor chamber is said first air discharge trough, a second air discharge trough, a main water inlet pipe and a main water discharge pipe, adjacent to the motor chamber are three auxiliary water inlet pipes having marked notches, in addition, the edge of the top cover plate has an annular slot for an "O" shaped seal washer to be placed in, when the top cover plate and the external shield cup are put together, the edge is covered up inside the external shield cup, allowing the "O" shaped seal washer to seal of an internal rim of the external shield cup;
• the multi-layered filtering member is made up of a diffusion plate and a plurality of filtering materials which are placed in different layers in a filtering cup, the center of the top layer of the diffusion plate is in a corresponding position with a U-shaped projecting portion of the water injector base having slotted holes arranged in an annular manner, on the bottom of the diffusion plate are water passage holes at the edges and a plate wall surrounding the diffusion plate.