Before the first fill: setting up correctly

The decisions made before the tub is filled for the first time affect how the first year goes more than most owners realise. Receiving site prep support from your cedar hot tub supplier will ensure a smooth experience from start to finish.

AlumiTubs provides planning, drawings, site prep, set up and lifetime support to its customers along with detailed tutorial videos helping with each step from receiving your tub to unpacking and rolling it into place, creating a hardwired connection on electric systems, or planning for a safe fire clearance on wood fired systems, to keeping it clean and caring for it. Every step is intended to keep families enjoying their hot tub effortlessly for decades to come. 

In this guide we'll detail how all-wood stave tubs compare to aluminum cedar hot tubs.

Site and surface

A cedar hot tub needs a flat, stable, well-drained base. An uneven base puts stress on the staves or rivets unevenly, which can lead to leaks. Compacted gravel, a poured concrete pad, or well-laid decking all work. What does not work well is a surface that settles, shifts seasonally, or retains standing water beneath the tub. Plan for insulaiton beneath the base of the tub and drainage that leads water away from the tub so that the bottom is in direct contact with a barrier. 

Allow clearance on all sides for access, and plan for drainage away from the base. A filled tub holding several hundred gallons of water is heavy, and the ground underneath will compress further once it is in place.

Water source

Know your water source before filling. Municipal tap water is typically close to balanced for pH and alkalinity, but should still be tested on arrival. Well water varies significantly in hardness and pH depending on local geology and may need adjustment before the chemistry is in range. Natural water sources such as lake or river water should also be tested before soaking.

Using a hose filter before filling removes heavy metals, chlorine from municipal supplies, and trace contaminants before they enter the tub. Starting with cleaner water reduces chemical demand from the first fill and is a worthwhile step regardless of the water source.

 The ideal ranges for hot tub water are as follows:

• Alkalinity 80-120 ppm
• pH Controls acidity 7.4–7.8
• Calcium Hardness Water stability 150–250 ppm
• Bromine 2–3 ppm

The first fills: tannins, wood movement, and what is normal

The first time a cedar hot tub is filled with water, several things happen simultaneously that can catch a new owner off guard. Understanding them in advance makes the break-in period considerably less stressful.

Cedar tannins

Cedar releases natural tannins into the water during the first several fills. The water will turn brown. This is normal and the water is safe to soak in. Tannins are not a hygiene concern and will not harm bathers or the tub's surfaces.

Tannins typically dissipate fully after four complete water changes. During this period, do not apply bromine or other chemical sanitizers to the water. In tubs with a non-porous interior surface, tannins in the presence of certain chemicals can cause surface staining. Continue balancing alkalinity, pH, and hardness throughout the tannin period, but hold off on sanitizer until the water runs clear after a fill.

Do not let the water sit for more than seven to ten days without changing it during this period. Keep cycling through the fills until the water is clear.

Wood swelling and the stave tightening process

An all-wood cedar stave tub is assembled dry and relies on the wood swelling when filled with water to create a watertight seal. This means a new tub may leak from between the staves during the first fill or two. This is expected and is not a sign of a defective tub. As the wood absorbs water and swells, the gaps close and the leaking typically stops within a few days.

During this break-in period, keep the tub filled continuously. Draining a stave tub that has not fully seasoned can allow the wood to dry and contract again, restarting the process. Some owners fill to a low level initially and gradually increase as the wood swells and the staves tighten.

If leaking persists beyond the first week, check the metal bands that hold the staves in place. These may need tightening with a band tool as the wood settles into its final shape.

If you own an AlumiTub The tannin process applies to the first fills of any tub with a cedar component. The key difference with an AlumiTub is that the watertight seal is provided by the welded and pressure-tested marine-grade aluminium interior, not by wood-to-wood compression. There is no stave-tightening period, no expectation of initial leaking, and no risk of the tub drying out and needing to re-swell. The tub arrives watertight and remains so. The cedar exterior is aesthetic and insulating rather than structural, which removes one of the most variable and unpredictable elements of traditional cedar hot tub ownership.

 

The first water balance

Once the tannins have cleared, begin the full water balancing routine. Test all four parameters, then adjust in sequence: alkalinity first, then pH, then calcium hardness, then bromine. Do not add bromine until the other three parameters are in range. Bromine applied to unbalanced water is significantly less effective, and correcting the chemistry afterward requires more chemical product than starting correctly would have.

The target ranges are alkalinity 80 to 120 ppm, pH 7.2 to 8.2 (with an ideal of 7.4 to 7.8), calcium hardness 100 to 250 ppm, and bromine 2 to 3 ppm.

Spring and summer: building the routine

The warmer months are the most forgiving time to develop a water care routine. Warm temperatures support comfortable soaking without the heating demands of autumn and winter, and water chemistry changes more slowly in a tub that is not being pushed to high temperatures continuously.

Establishing testing habits

The first few months are the time to make testing automatic. Test two to three times per week and before each soak if the tub is used periodically. The goal is not to react to problems but to catch small drifts before they become larger ones. Water that is slightly out of range requires a small correction. Water that has been out of range for a week or two requires a much larger intervention, and sometimes a full change.

Summer water care demands

Summer use brings its own pressures on water quality. Sunscreen, body oils, increased bathing frequency, insects, pollen, and warm ambient temperatures all accelerate the organic load in the water. Rinse off before every soak. Skim the surface after each use. Keep the lid on whenever the tub is not in use.

Filter checks should happen weekly during heavy summer use. A filter that is working hard in warm weather can become soiled faster than the usual fortnightly cleaning cycle suggests. A spare filter on hand allows rotation without taking the tub out of service.

Wood care in the warmer months

For an all-wood stave tub, summer is the time to watch for seasonal movement. Hot, dry spells cause the cedar to contract, which can reopen the micro-gaps that tightened during the initial fill. If a tub is left empty for extended periods during summer, the staves can dry and shrink noticeably. Keep the tub filled, or if it must be drained for an extended period, do so knowing that re-swelling may be needed on the next fill.

The exterior of the tub benefits from occasional cleaning to remove debris, mould, and surface weathering. A gentle rinse and brush-down is sufficient. Cedar treated with a clear sealant or oil holds its colour longer, though many owners prefer to allow the natural silver-grey patina to develop without intervention.

If you own an AlumiTub The wood movement concerns that apply to stave tubs are not a factor with an AlumiTub. The cedar is exterior cladding secured to an aluminium structure, not the watertight body of the tub. Dry spells, extended draining, and seasonal temperature swings do not affect the integrity of the vessel. Summer maintenance is primarily about water care and cleaning rather than monitoring the structural material.

 

Heading into autumn: preparation matters

Autumn is the transition season, and the decisions made during it determine how the first winter goes. Many first-year owners underestimate this window.

Inspecting the staves and bands

Before temperatures drop, inspect an all-wood stave tub for any gaps between staves that may have opened during the summer. Check that the metal bands are secure and evenly tensioned. A small leak that is manageable in autumn can become a serious problem when freezing temperatures arrive, as water expanding in a gap can widen it significantly.

Any wood that shows signs of softening, discolouration beyond normal weathering, or surface mould that has penetrated the wood rather than sitting on the surface should be assessed. Catching deterioration early is far easier than managing it after a winter.

Deepening the water care routine

As soaking frequency typically increases heading into autumn, the water care routine needs to keep pace. Consider adding a monthly enzyme-driven conditioning treatment to the water. This reduces organic load and helps stabilize chemistry, which in turn reduces the amount of bromine needed to maintain safe water. The principle is prevention: keeping the chemistry stable through a busier soaking season is significantly less effort than recovering water that has degraded.

Ensure the filter is clean before the heavier use of autumn and winter begins. A fouled filter heading into the coldest months is one of the most common causes of water problems when the tub is being used most heavily.

 

The first winter: the most demanding season

Winter is where cedar hot tub ownership asks the most of you, and where the difference between a well-chosen, well-maintained tub and a poorly designed one becomes most apparent.

Freeze risk in all-wood stave tubs

Water left in an all-wood stave tub that freezes can cause serious damage. As water expands on freezing, it exerts significant outward pressure on the staves and the band system holding them together. This can cause cracking, band failure, or permanent distortion of the stave alignment. Even a partial freeze is damaging.

For a tub that will be unused through winter, the safest approach is to drain it completely. This requires accepting that a re-swelling period will be needed when it is refilled in spring. For a tub that will be used through winter, the fire needs to be managed carefully to ensure the water never drops to a temperature where freezing can begin.

Heat retention and fuel demands

An all-wood stave tub without additional insulation loses heat significantly in cold weather. The wood itself provides some thermal resistance, but not enough to prevent rapid heat loss overnight or between sessions. Owners of uninsulated tubs in cold climates often find that keeping the water at a usable temperature through winter requires near-continuous fire management, which is demanding and fuel-intensive.

An insulated lid makes a substantial difference. Without a lid, heat loss through the water surface is enormous. With a well-fitted, insulated lid, the same tub retains heat for hours longer after a fire burns down, which reduces the number of fires needed to maintain temperature and the amount of wood consumed across the season.

If you own an AlumiTub The AlumiTub's 360-degree insulation, drawn from three materials working together, the cedar exterior, the insulation layer, and the marine-grade aluminium structure along with its stainless steel components is built in rather than added seasonally. Overnight wood fired hot tub heat loss with the insulated lid in place is approximately two to three degrees Fahrenheit regardless of outdoor temperature. This changes the winter experience meaningfully: the tub retains heat efficiently without supplemental insulation wrapping, and the fire management requirement between sessions is modest. AlumiTubs are tested and used in conditions down to minus forty-four degrees Celsius. Freeze risk in a properly managed AlumiTub is substantially lower than in an all-wood stave tub because the insulation holds temperature for longer between uses. For the Electric hot tub and Hybrid models, automatic freeze protection engages when temperatures drop, providing protection without any active management required.

 

Water care in cold weather

Cold weather slows bacterial growth, which tends to reduce sanitizer demand somewhat. However, chemistry still drifts, and the consequences of a poorly balanced tub in winter are no different from any other season. Continue testing two to three times per week and before soaking.

One practical point: bromine can dissipate quickly from hot water, particularly in cold ambient conditions where the temperature differential is large. Always retest before soaking rather than relying on a reading from a day or two prior.

If the tub is drained for winter, flush the plumbing or filtration lines if the tub has a filtration add-on. Water left in lines or the filter housing can freeze and cause damage that is not visible until spring.

 

End of year: what a good first year looks like

By the end of the first year, a well-managed cedar hot tub should have an established water care routine that takes under twenty minutes per week of active attention, been used through all four seasons with growing confidence, and given a clear picture of what maintenance the coming years will involve.

A tub that has been well-chosen and well-cared for in year one typically becomes easier in year two. The novelty of the process gives way to familiarity. The seasonal transitions feel less significant once you have been through them once. The water care routine becomes automatic.

Season	Key focus for all cedar tubs	Additional considerations for stave tubs
First fills	Tannin period: drain and refill without sanitizer until water runs clear	Allow wood to swell and staves to tighten; expect initial minor leaking
Spring / Summer	Establish testing routine; manage increased organic load from summer use	Monitor for stave movement in hot dry spells; keep tub filled
Autumn	Inspect before winter; deepen maintenance routine; clean filter thoroughly	Check bands and stave alignment; address any gaps before freeze risk arrives
Winter	Manage heat retention; retest bromine frequently in cold conditions	Drain fully if unused; manage freeze risk actively if in use; consider exterior insulation

 

How the experience differs with an aluminium-lined cedar tub

Most of the considerations in this guide apply to cedar hot tub ownership generally. Some of them, particularly the structural ones, are specific to all-wood stave construction.

An AlumiTub uses Canadian Western Red Cedar as the exterior finish and insulating layer, not as the watertight body of the tub. The structural and watertight element is a marine-grade aluminium interior, riveted, welded, pressure-tested, and guaranteed leak-free for twenty-five years. This distinction changes a specific set of first-year experiences.

What is the same

 

What is different

 

The first year for an AlumiTub owner still involves the learning curve of water chemistry and the seasonal rhythm of any outdoor hot tub. What it removes are the structural variables: the leaking that is expected and managed, the wood movement that is monitored, the winterising that is genuinely complex in an all-wood construction. Those are replaced by a predictable, consistent vessel that behaves the same way in January as it does in July.