How to Clean a Cedar Hot Tub: Surfaces and Materials

Cleaning a cedar hot tub takes a soft cloth and a mild plant-based cleanser on the aluminum, a soft-bristle brush on the cedar, and a full surface clean every three to four months timed with a water change. Nothing abrasive, no pressure washing, and never vinegar.

This guide covers cleaning the tub itself: the aluminum surface, the cedar, and everything around it. Water chemistry is a separate job, and it is covered in how to keep hot tub water clean.

Most of this applies to every AlumiTub, whichever way it heats. The firebox section further down is for Wood Fired and Hybrid owners.

The good news is that an AlumiTub is easier to clean than a conventional spa, and for a structural reason. The marine-grade aluminum interior is smooth and non-porous, so there is nowhere for bacteria to establish and no complex plumbing to harbor it. Most of the work is a wipe rather than a scrub.

Start before you get in

Water does not get dirty on its own. Almost everything that clouds it arrives on people, so a few habits do more than any cleaning routine afterward.

• Rinse off first. As in Japanese onsen bathing, a quick wash before you get in removes the oils, lotions and dead skin that would otherwise end up in the water.
• Rinse your feet. A bucket beside the tub and a pair of sandals keeps dirt, grass and grit out. Grit is the thing most likely to mark an aluminum surface, because it turns an ordinary wipe into an abrasive one.
• Wash swimwear without harsh detergent. Residue in the fabric transfers straight into the water.
• Leave lotions and oils off. Sunscreen and body oil are the usual cause of cloudy water and a tide line around the waterline.
• Keep the lid on when you are not in it. A lid does more for cleanliness than anything you can add to the water, and a small handheld net deals with whatever falls in from the trees above.

Cleaning the aluminum

The interior wants a mild, low-foam, plant-based, pH-balanced cleanser and a soft cloth. The Tub Cleanser in the Good Clean Living Water Care kit is formulated for it. Every three to four months is enough for most owners, timed to coincide with a water change.

Three details matter more than the product:

• Wipe while the surface is still wet. Never let a cleanser dry on the tub.
• Rinse thoroughly afterward. Residue left behind is the thing that causes marks, not the cleanser itself.
• Nothing abrasive, ever. No scouring pads, no wire wool, no sanding, no pressure washing. Marine-grade aluminum protects itself with a thin oxide layer, and abrasives are what take that layer off.

Do not use vinegar. It appears in a lot of general hot tub advice and it is the wrong call on aluminum, because prolonged acid contact attacks the surface rather than cleaning it. The same applies to descalers and any product intended for acrylic spas.

If you want the mechanism rather than the rule, what causes pitting in an aluminum hot tub sets out what actually damages the oxide layer, and what leaves it alone.

Cleaning the cedar

The seats, the exterior cladding and, on a Wood Fired or Hybrid, the firebox fence are Canadian Western Red Cedar, and they are more forgiving than the aluminum. A soft-bristle brush and a rinse with a hose deals with most build-up. Work with the grain rather than across it.

Cedar silvers as it ages. That is the wood weathering, not a fault, and it can be left alone, sanded back and refinished, or sealed to hold the original tone. Mineral oil brings out the grain if you would rather keep the color warm.

Two rules on finishes. Never apply paint, stain or any treatment to the interior seats or the firebox fence, since it will leach into the water. And anything you use on the exterior must be copper-free, because copper reacts with the aluminum structure. Keep the base boards clear of standing water and soil while you are at it.

The firebox and chimney, on a Wood Fired or Hybrid

Clear the ash regularly with the scoop supplied. A firebox that is full of ash draws poorly, burns cooler and takes longer to bring the water up to temperature, so this is a performance job as much as a cleaning one.

Keep the chimney clear, and check the spark-arresting cap at the start of each season.

Never drain below the fill line until the firebox has fully cooled. That applies whether you are emptying for a clean, for a water change, or for the winter.

The equipment housing, on an Electric or Hybrid

The heater, pump and filtration live inside the cedar steps, out of the weather. Keep the housing clear of leaves and debris so air can move around it, and follow the filter cleaning interval rather than the look of the water. A filter that looks fine can still be due.

The advantage of that arrangement shows up here: everything is concealed but reachable, so cleaning around the equipment, changing a filter or replacing a part is a job you can do by hand rather than a call-out.

Around the tub

Rinse the steps, the surround and anything else that comes into regular contact with bare feet. Most of what ends up in the water arrives on the way in.

How often, realistically

A full surface clean belongs with a water change, so the frequency follows how you run the tub. On a filtered tub that is every three to four months. Filling and emptying around each visit means a quick rinse each time and a proper clean far less often.

For how long water actually lasts and what keeps it clear in between, see how often you should change hot tub water, and for an honest picture of the whole routine, how hard a wood fired hot tub is to maintain.

Reserve your wood fired hot tub, or ask us a question.