7″ × 21.0625″ Replacement Filter Cartridges

Every cartridge in our index that measures 7″ across by 21.0625″ tall, all 1 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: 7″ × 6.5″ · 7″ × 9.125″ · 7″ × 10.75″ · 7″ × 14.75″ · 7″ × 17.625″ · 7″ × 19″ · 7″ × 19.625″ · 7″ × 25.5″ · Browse all sizes →