Cedar ice bath

A cedar tub, steel hoops, a drain, a lid. That is the whole product. There is nothing to break because there is nothing in it, which on a remote site with unreliable power is a serious feature rather than a compromise.

The catch is ice, and we are going to be direct about it, because the arithmetic surprises people and we would rather it surprised you now than in month three.

The honest ice arithmetic

Roughly 20–30 kg of ice takes a 700-litre tub of Lombok tap water down to about 8 °C. Tap water here runs around 27 °C, so you are not chilling from cold — you are chilling from nearly body temperature, and that is why the number is that big.

Do that every morning and you are buying somewhere near a tonne of ice a month, hauling it, and storing it. If you use the tub daily, a chilled plunge pays for the difference within a couple of years and holds a stable temperature besides. If you use it twice a week, or you are off-grid, or you simply do not want a machine in your garden, cedar is the right call and the maths agrees with you.

Why cedar

Western red cedar is naturally rot-resistant, dimensionally stable, and insulating enough that a lidded tub holds its temperature meaningfully longer than a plastic one — which directly reduces how much ice you buy. It also smells like a cedar tub, which is not an engineering argument but is a real one.

The hoops are A4/316 stainless. Not A2 — see what salt air does to fixings. The staves swell shut in the first few fills; a new tub weeping slightly on day one is normal and stops.

Keeping it clean without plant

With no circulation and no filtration, the rule is simple: shower before you get in, keep the lid on, and drain it regularly. How regularly depends entirely on how many people use it — one person twice a week is a very different problem from a surf camp running eight bodies through it on a Saturday.

You can dose it manually, but cold water changes how sanitiser behaves and it is easy to get wrong. Read cold plunge water treatment before you start pouring anything in. For any shared or commercial use, we will steer you to the chilled plunge with proper filtration instead — not to upsell you, but because manual dosing of a shared tub is not a system we want our name on.

Pairing and siting

Cedar tub plus barrel sauna is the classic pairing and the cheapest complete hot-and-cold setup we build. Cedar tub plus infrared cabin is the low-power version — a full contrast setup that runs on a standard villa supply with no PLN upgrade at all.

Site it in shade, on a base that carries the filled weight, three to five metres from the hot room, with somewhere for the drain water to actually go. Same rules as everything else. If you want the whole sequence designed at once, that is a wellness zone.