Cleaning a hot tub filter, step by step

1. Turn the tub off, as Hot Spring, Bullfrog, Master Spas and Sundance all say, and never run the pumps without the filter in: debris gets drawn into the pumps.
2. Clear floating debris from the filter well before you lift anything out; Hot Spring says debris can get into the internal plumbing.
3. Unscrew the cartridge and lift it out.
4. Hose each pleat with a spray nozzle, from the top down. Bullfrog says work the inside first, then the outside.
5. Once a month, soak it in a spa filter cleaner per the label to strip oils and minerals.
6. Rinse, let it dry if you have a spare, and reinstall. Jacuzzi says to dunk its cartridges first to clear trapped air.

• Don't scrub it with a brush; Bullfrog says brushing can damage the filter media.
• Don't soak inserts that aren't meant for it. Master Spas' EcoPur insert is rinse-only, never filter cleaner.
• Don't remove the filter standpipes or suction fittings; Hot Spring warns against both.

None of the six manuals mentions a dishwasher or vinegar for cartridges; they call for a hose and a spa filter cleaner. White calcium on a filter is a clue: Bullfrog reads it as a sign of high pH, to fix before it scales the heater. See hot tub pH.

Because everything downstream depends on flow. Hot Spring's manual says a clogged cartridge can weaken the jets, limit flow and trip the high-limit thermostat, which shuts down the whole tub. A spare set lets one dry while the other works, and Master Spas says drying may extend cartridge life. When cleaning no longer restores it, see when to replace a hot tub filter.