13.5 Sq. Ft. Cartridge Filter

The Northern Bay 13.5 Sq. Ft. Cartridge Filter is a compact hot tub filter designed to keep spa water clear by trapping fine debris in a relatively small filtration area, ideal for plug‑and‑play or smaller Northern Bay spa models. It is best used as a replacement cartridge when the original filter shows buildup, discoloration, or your spa water begins to look cloudy.