Wastewater filters and wastewater filtration systems specifically adapted for their use

An apparatus comprising:

• a wastewater treatment tank;
• wastewater in the wastewater treatment tank;
• and
• a filter cartridge mounted in the wastewater treatment tank, submerged in the wastewater, and comprising:
• a peripheral frame;
• a first filter media sheet attached to the peripheral frame;
• a second filter media sheet attached to the peripheral frame in spaced face-to-face relation to the first filter media sheet such that the peripheral frame, the first filter media sheet, and the second filter media sheet combine to define a filter interior volume with the first filter media sheet having a first exterior media surface facing away from the filter interior volume and a first interior media surface facing towards the filter interior volume, and with the second filter media sheet having a second exterior media surface facing away from the filter interior volume and a second interior media surface facing towards the filter interior volume;
• a grid of first fins attached to the peripheral frame external to the filter interior volume, a portion of the grid of first fins and projecting away from the first exterior media surface at an oblique angle;
• a grid of second fins attached to the peripheral frame external to the filter interior volume, a portion of the grid of second fins and projecting away from the second exterior media surface at an oblique angle;
• and
• a filtered water outlet in fluid communication with the filter interior volume.