The Unicel C-7375 delivers 75 square feet of filtration across 216 pleats of Reemay® 2033 polyester media. Built to meet or exceed OEM specifications, it’s the replacement cartridge for new-style Caldera® Spas, taking the place of Caldera parts 73531 and 1019301.
Filtration is the quiet backbone of clean spa water. Every soak leaves behind body oils, lotions, hair, and fine debris, and the cartridge is what removes all of it before it clouds the water, feeds bacteria, or coats your plumbing. When a filter is worn or clogged, the effects spread everywhere: dull water, higher chemical use, softer jets, and a pump and heater straining against restricted flow.
This is a substantial cartridge — 14-3/4 inches tall with 75 square feet of filtering surface — sized for the demands of a full-size Caldera spa. A semi-circular handle molded into the top makes lifting it out for cleaning effortless, while the 2-11/16 inch open bottom seats into the housing for a proper seal. Add Reemay’s trilobal fibers, uniform pleat folds that keep flow strong and pressure loss low, and chemical-resistant end caps, and you get a cartridge built to perform through cleaning after cleaning. Made in the USA.
Pro Tip: This is the “new style” Caldera cartridge — verify yours before ordering. Caldera changed filter designs across model years, and this cartridge covers the newer configuration with a handle on top and a 2-11/16 inch open bottom. The fastest check is to pull your current filter and look at the ends: if it has a molded handle and an open bottom of that size, this is your replacement. If the numbers 73531 or 1019301 appear on it, you’re in the right place.
Brand
UNICEL®
