Pentair FNS Plus Filter Lid Assembly, 48 sq ft | 170021 Smart Company Add this algaecide after balancing

Add this algaecide after balancing pH and alkalinity and with the pump running

This impeller is matched to the motor and wet end for proper flow performance

xm systems and certain in

then folds down for compact storage

Pentair FNS Plus Filter Lid Assembly, 48 sq ft | 170021 Smart Company Add this algaecide after balancingWhat This Part Is Used For Pentair 170021 Lid Assembly 48Sqft, FNS Plus is a replacement lid for compatible FNS Plus 48Sqft filters. It covers and seals the filter tank. Why This Part Matters Maintaining a proper seal prevents pressure loss and water leaks. A damaged lid can disrupt filtration efficiency. Replacing it helps restore consistent filter performance. Key Features and Specifications Pentair manufacturer part number 170021 For FNS Plus