Unicel C-8411 75 sq ft Replacement Filter Cartridge

The Unicel C-8411 is a 75 square foot replacement cartridge element. It measures 8-15/16 inches in outside diameter and 17-3/8 inches long, which makes it one of the shorter, wider cartridges rather than a tall slim one.

Getting the fit right

Square footage on its own does not decide whether a cartridge fits. Two 75 sq ft elements can be completely different shapes, so measure the old cartridge and match the outside diameter and the length before ordering. Unicel lists this element against Hayward, Pentair and Waterway filters.

When to replace rather than clean

A cartridge is finished when a proper soak stops bringing the filter pressure back down, or when the pleats have flattened, split or gone permanently gray. At that point the media is loaded past recovery, and no amount of hosing restores the flow.