Caldera 31489 | 30 sq ft Spa Filter Cartridge Brand_Pool Marvel easiest algae you ever deal

easiest algae you ever deal with is the algae that never forms

unthreaded collar that seals by close tolerance against a matching socket in the filter well

swimmers can jump back in the pool in just 15 minutes after treatment

A single 16 oz bottle treats a standard spa cover roughly 12 to 16 times — about a year and a half of monthly maintenance

Caldera 31489 | 30 sq ft Spa Filter Cartridge Brand_Pool Marvel easiest algae you ever dealThe Caldera 31489 filter cartridge delivers 30 square feet of pleated filtration for cleaner, clearer spa water. It's one of the most widely compatible cartridges in the Watkins family of spa brands, serving a broad range of models across decades of production so it's a dependable replacement to keep on hand. Filtration is the quiet backbone of good spa water. Every soak leaves behind body oils, lotions, hair, and fine debris, and the cartridge is