A fluid treatment apparatus includes a base portion, a medium or media, and an elongated support portion. The base portion has a first end, a second end, and a side with an exterior surface. The first end has an inlet and outlet for receiving and dispensing a water flow, respectively. The medium or media is spaced within the base portion and receives fluid through the inlet, treats the fluid, and dispenses the fluid through the outlet. The elongated support portion extends from the second end of the base portion and has a sidewall. The sidewall has an exterior facing surface that is substantially aligned with the exterior surface of the side. The elongated support portion maintains a latch assembly location for engaging a filter head assembly and is configured to withstand torsional forces applied by the user for engagement and alignment with an elongated receiving cavity of an appliance.