Structure of aquarium filter

An aquarium filter device for providing filtered water to an aquarium, the aquarium filter device comprising an outer filter cloth, an inner filter net, an activated carbon filter sheet disposed between the outer filter cloth and the inner filter net, a space defined by the inner filter net, and a water inlet connected to a single opening of the space wherein

• the outer filter cloth includes at least one layer of nonwoven fabric having a plurality of first pores and a first density;
• the activated carbon filter sheet including at least one layer of activated carbon material;
• the filter net includes at least one layer of resin foam having a plurality of second pores greater than the first pores, and a second density less than the first density;
• and
• a water guiding pipe having a first end immersed in the aquarium and a second end connected to the water inlet;
• wherein water in the aquarium is configured to flow though the water guiding pipe and the water inlet into the space and further flow through the inner filter net, the activated carbon filter sheet, and the outer filter cloth.