Unicel 4000 Series 19 sq. ft. Replacement Filter Cartridge | 4CH-21 Pool Lighting Heavy duty

Heavy duty

SM & SMBW 4000 Series pool and spa DE filters

Top Mount HiFlow Valve

After initial dose

United Chemical Pool Stain Treat - 2 Lbs

Unicel 4000 Series 19 sq. ft. Replacement Filter Cartridge | 4CH-21 Pool Lighting Heavy dutyThe Unicel 4CH 21 is a 4000 Series 19 sq. ft. replacement filter cartridge engineered for top load spa and hot tub filtration systems with a 1 1 2" MPT threaded suction connection. With 158 pleats of 3 oz. Reemay 2033 polyester media, this cartridge delivers consistent particle capture and reliable water clarity in compact spa filter housings. The molded cone handle on top simplifies removal at service time, while the 1 1 2" male pipe thread bottom