8.6875″ × 18.1875″ Replacement Filter Cartridges

Every cartridge in our index that measures 8.6875″ across by 18.1875″ tall, all 2 of them. Compare brands side by side and cross-reference the Pleatco, Unicel, and Filbur numbers before you order.

One catch: diameter and length are the dimensions that get most of the attention, but end-cap style (open, closed, or with a hole) has to match the housing too. A cartridge that's technically the right size won't seal if the cap is wrong, so check both before you buy. Here's how to measure a cartridge.

Close sizes: 8.5″ × 7.25″ · 8.5″ × 10.5″ · 8.4375″ × 18″ · 8.9375″ × 21″ · 8.9375″ × 23.3125″ · 8.375″ × 14″ · 8.375″ × 19″ · Browse all sizes →