Composite sock filter for aquariums

A vertical sock filter for an aquarium filter assembly, the sock filter comprising an annular collar coupled to filter material, the filter material comprising upper filter material and lower filter material, wherein the upper filter material is at least about twice as porous as the lower filter material, the assembly comprising an opening for receiving the sock filter, the annular collar comprising an annular neck and an annular rim, the filter material extending vertically through the opening when the annular rim is placed on an upper surface of the assembly, the annular rim comprising a notch and the assembly comprising a key for aligning the sock filter in the assembly.

A vertical sock filter for an aquarium filter assembly, the sock filter comprising an annular collar coupled to filter material, the filter material comprising upper filter material and lower filter material, wherein the upper filter material is at least about twice as porous as the lower filter material, the assembly comprising an opening for receiving the sock filter, the annular collar comprising an annular neck and an annular rim, the filter material extending vertically through the opening when the annular rim placed on an upper surface of the assembly, the annular neck and opening comprising chords for aligning the sock filter in the assembly.

A vertical sock filter for an aquarium filter assembly, the sock filter comprising an annular collar coupled to filter material, the filter material comprising upper filter material and lower filter material, wherein the upper filter material is at least about twice as porous as the lower filter material, the assembly comprising an opening for receiving the sock filter, the filter material extending vertically through the opening when the annular collar is placed on an upper surface of the assembly, the assembly and annular collar together comprising mating male and female components for aligning the sock filter in the assembly, wherein the lower filter material has a pore size within a range of about 50-200 microns and the upper filter material has a pore size within a range of about 250-1000 microns.

A vertical sock filter for an aquarium filter assembly, the sock filter comprising an annular collar coupled to filter material, the filter material comprising upper filter material and lower filter material, wherein the upper filter material is at least about twice as porous as the lower filter material, the assembly comprising an opening for receiving the sock filter, the filter material extending vertically through the opening when the annular collar is placed on an upper surface of the assembly, the assembly and annular collar together comprising mating male and female components for aligning the sock filter in the assembly, wherein the upper filter material represents 10-50% of the filter material.