The Pentair Tank Lid Assembly (178582) is the OEM replacement lid for the Clean & Clear Plus 520 sq. ft. cartridge filter and the Quad D.E. 100 filter. If your filter lid is cracked, warped, or no longer seals correctly, this is the direct replacement part. ⚠️ IMPORTANT: MANUFACTURING DATE APPLIES — CLEAN & CLEAR PLUS 520 This lid assembly is correct for Clean & Clear Plus 520 sq. ft. filters manufactured after November 1998. If your filter was manufactured before that date, verify the part number on your existing lid before ordering. The tank lid assembly seals the top of the filter tank, maintaining system pressure and preventing water loss during filtration. A damaged or improperly seating lid allows air infiltration and pressure loss, reducing filtration efficiency and potentially causing pump cavitation. Replacing the lid assembly restores a proper pressure-tight seal at the tank opening. Specifications Pentair Part Number 178582 Part Name Tank Lid Assembly, 520 sq. ft. Part Category Tank Components Quantity Included 1 (Each) Fits Into Brand Equipment Line Model / Part Number Notes Pentair Clean & Clear Plus — 520 sq. ft. Cartridge Filter CLEAN & CLEAR PLUS 520 Filters manufactured after 11/98 only. Verify manufacturing date before ordering. Pentair Quad D.E. Filter 100 — Quad D.E. Series Quad 100 Lid for Quad 100 Compatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment's manual or on the original part itself before ordering. Pro Tip Before installing the new lid, inspect the lid O-ring seat on the tank collar for cracks or debris — a damaged seat will prevent even a new lid from sealing correctly. If the lid O-ring is not included or shows any deformation, replace it at the same time to avoid a return service call. Match the part number molded or stamped on your existing lid to confirm 178582 is the correct replacement before ordering.
