Hot Spot Hot Tub Replacement Filters

Hot Spot is Watkins Wellness's value line, sold through Hot Spring dealers but filed separately in the filter cross-references because the sizing does not match. The Relay, Rhythm, and Tempo tubs carry Watkins OEM number 31489, a 30 sq ft cartridge 5-7/8 inches across and 10-1/2 inches long, sold as Pleatco PWK30, Unicel C-6430, and Filbur FC-3915.

Older Hot Spot tubs take a different size. Unicel files some of them under Watkins OEM 33521, a 25 sq ft drop-in (Unicel C-4326, Pleatco PRB25-IN), so if your tub predates the current line, read the end cap rather than assuming the 30 sq ft cartridge fits. The 3 Hot Spot models below cover 2008 onward.