Abstract: A filter assembly for filtering water in an aquatic structure having a housing with a flow inlet and a flow outlet and filter media between the flow inlet and the flow outlet. A vortex distributor is supported in the housing to distribute fluid evenly over the filter media and partially separate debris from the fluid. The vortex distributor has a conically shaped body portion with an upper side, a lower side and a vortex opening. The vortex opening is substantially centered in the body portion and a plurality of vanes are supported on the upper side of the body portion around the vortex opening, the vanes curving away from the vortex opening to form a substantially planar upper surface.

Abstract: A liquid level assembly for controlling liquid level has a switching mechanism responsive to the liquid head to activate a pump. A housing assembly has an internal cavity in which the switching mechanism is supported, the housing assembly having an open end sealed by a diaphragm seal having a flexible planar portion that transmits head pressure to the switching mechanism. The diaphragm seal also has a peripheral web portion and a flexible bellows portion connecting the flexible planar portion and the peripheral web portion. The peripheral web portion has a peripheral sealing bead that is sealingly compressed against a groove in the housing assembly, and a plurality of knob members extend from the peripheral web to press against the switching assembly, thereby accommodating manufacturing dimensional tolerances of the switching mechanism.