The Tri-X 73178 replacement filter is a factory-original ceramic cartridge filter for Hot Spring Spas, made by Watkins Mfg. Its ceramic pleats are engineered to filter twice the water per minute of a standard paper filter — delivering noticeably clearer water, less frequent cleaning, and an estimated five-year lifespan. Your filter is the hardest-working component in your spa. It's what pulls body oils, lotions, hair, and fine debris out of the water before they cloud it, feed bacteria, or coat your plumbing. A tired or undersized filter forces everything else to compensate: the water goes dull, you burn through more chemicals, and your pump and heater work harder against restricted flow. Getting the filter right is one of the highest-leverage things a spa owner can do. That's where the Tri-X design stands apart from the common polyester "paper" filter. Its rigid ceramic media captures twice as much from the water while allowing higher flow to the jet pumps, and it's durable enough to be cleaned with high-pressure water — or simply run through your dishwasher. Better clarity, less maintenance, and years of service from a single cartridge. Pro Tip: Think in cost-per-year, not cost-per-filter. A Tri-X costs more up front than a polyester cartridge, but a paper filter is typically replaced every year or so while a properly maintained Tri-X can run about five. Spread across its service life, the ceramic filter is usually the less expensive choice — and you get better water the entire time. Brand Hot Spring®
