Aquarium and non-disruptive filtration system

An apparatus, comprising:

• a tank having a closed end and an open end;
• a filter housing comprising a base plate and a sidewall, the filter housing being disposed within an interior of the tank, and longitudinal edges of the sidewall being affixed to a surface of an interior sidewall of the tank to enclose a first portion of the tank, the sidewall comprising a plurality of inlets;
• a filter cartridge dimensioned to be removably positioned between the sidewall and the surface of the tank sidewall, the filter cartridge partitioning the enclosed first portion of the tank into a first chamber and a second chamber, the first chamber being in fluid communication with a second portion of the tank through the inlets;
• a pump disposed within the second chamber, the pump having an input in fluid communication with the second chamber, and an output connected to a proximal end of an elongated tube;
• and
• a reservoir dimensioned to be removably positioned within the second chamber, the reservoir being connected to a distal end of the elongated tube and including an outlet that engages the sidewall, wherein:
• the second portion of the tank stores water,
• the pump operates to mechanically draw the water from the second tank portion into the first chamber through the inlets, and across the filter cartridge into the second chamber;
• the pump operates to mechanically pump the drawn water through the elongated tube and into the reservoir;
• and
• the reservoir discharges the pumped water into the second tank portion through the outlet.