Aquarium filter assembly, components thereof, and methods

A dual filter assembly for use in filtering aquarium water, the dual filter assembly comprising:

• (a) a cassette including a first edge and a second edge, and a bottom edge extending between the first and second edges;
• the cassette including a bio-filter holder arrangement and a filter cartridge holder arrangement;
• (i) the filter cartridge holder arrangement including,
• (A) a first flange arrangement being angled inwardly from the first edge as the first flange arrangement extends from the first edge toward the bottom edge;
• and
• (B) a second flange arrangement being angled inwardly from the second edge as the second flange arrangement extends from the second edge toward the bottom edge;
• (b) a biological host media filter element removably held in the bio-filter holder arrangement for filtering aquarium water, when used in an aquarium;
• and
• (c) a filter cartridge for filtering aquarium water when used in an aquarium;
• the filter cartridge being separate from the biological host media filter element the filter cartridge removably held in the filter cartridge holder arrangement by the first flange arrangement and second flange arrangement;
• the filter cartridge including,
• (i) a frame;
• and
• (ii) a media pack secured to the frame;
• the media pack being between and against the first flange arrangement and second flange arrangement.