Unicel C-8399 | 100 sq ft Caldera Spa Filter Brand_Ooni start with the 2 lb

start with the 2 lb size — not the 5 lb

so it stays active in the water longer and keeps working between treatments

eliminating the need for many of the individual balancing treatments you might otherwise use

5 lb container — the size most chlorine-system owners settle on after their first refill

1 x DuraVent 46DVA-16AB Pipe Extension - 16"

Unicel C-8399 | 100 sq ft Caldera Spa Filter Brand_Ooni start with the 2 lbThe Unicel C 8399 is a large capacity spa filter cartridge delivering 100 square feet of filtration across 259 pleats of Reemay 2033 polyester media, capturing debris down to an average of 20 microns. Built to meet or exceed OEM specifications, it's the replacement cartridge for Caldera Spas, taking the place of Caldera part 1039607. Filtration is the quiet backbone of clean spa water. Every soak leaves behind body oils, lotions, hair, and fine