How to clean a hot tub, inside and out

Oils, lotions and hair products float and leave a ring at the waterline. Hot Spring says wipe it with a clean rag; if it is heavy, drain and clean the shell with a spa surface cleaner. Master Spas adds an enzyme product to the water to break the oils down. Avoid anything that leaves soap in the water, which turns into foam.

Less than you think, and the makers disagree on details. Hot Spring allows only plain water and two named spa products, and rules out household cleaners, alcohol, abrasives and solvents, window cleaner included. Bullfrog allows mild dish soap or window cleaner for normal cleaning and a mild acrylic cleaner for stains. Both bar alcohol, solvents and abrasive cleaners, and both say to rinse cleaners off well. Follow your own manual; shell damage from the wrong product isn't covered by Hot Spring's warranty.

For white scale, Master Spas says scrub with a multi-purpose spa cleaner or white vinegar and a soft cloth once the tub is empty. CDC's hot tub guidance calls for scrubbing every surface each time a tub is drained.

Most jets twist out. Master Spas says to turn them counterclockwise to remove them, then soak them in white vinegar to clear grit and mineral deposits, especially when a jet gets hard to turn. Don't pull suction fittings or filter standpipes; Hot Spring warns against removing either. For the pipes behind the jets, see biofilm and line flushing.

Pull them off their clips whenever you clean the shell, wash body oils off with mild soap and water, and rinse thoroughly. Hot Spring also says to take them out during a superchlorination or when the tub sits unused, since chemicals bleach them. Then refill and rebalance: see how to drain and refill a hot tub.