Hot Tub Water Care Explained: Filtration, UV, Ozone and Filter Cleaning

A hot tub in your garden is about relaxation, warmth and a bit of a break from everyday life. To keep the water feeling consistently fresh and pleasant, though, you need more than the occasional top-up of pflege products. Genuinely stable hot tub water care comes from a coordinated system: filtration, a UV system, ozone and a regular filter clean.

Many people think of chlorine or other disinfectants first when they hear "water care". But the mechanical job done by the hot tub filter is what everything else builds on. If the filter isn't doing its work, even the best chemistry will struggle to keep the water in balance.

How modern hot tub water care fits together

Modern hot tubs like the Canadian Spa Company range run on several components that work together. Each one has its own job in the overall water care system.

1. The hot tub filter — the centrepiece

The filter handles the mechanical cleaning of the water. As the water circulates, particles are caught reliably. Typical residues in spa water include:

• Skin cells
• Body oils and lotions
• Cosmetic residue
• Pollen and dust
• Other organic particles

The fine pleats of a filter cartridge create a large surface area to trap that debris — but it's also where build-up accumulates. If it isn't cleared regularly, water flow drops and the whole system loses efficiency.

2. UV technology for extra hygiene

An integrated UV system passes the circulating water under ultraviolet light, reducing microorganisms and supporting disinfection.

Benefits of a UV system:

• Lower microbial load
• More stable water readings
• Reduced chemical demand

UV doesn't replace cleaning the filter — it backs it up.

3. Ozone for oxidising organic load

Ozone in a hot tub acts as a strong oxidiser. It breaks down organic matter, reduces odours and takes some of the load off the water chemistry. Combined with a clean filter, it makes for a much more stable water balance.

Why regular filter cleaning matters so much

Cleaning the filter is one of the most important routines in hot tub maintenance. Every time the spa is used, residues build up between the pleats. From the outside the filter often still looks clean, but build-up and biofilm can be developing inside.

A clogged filter often leads to:

• Cloudy spa water
• Higher chemical use
• Poor water circulation
• Higher electricity costs
• More strain on the pump

Regular filter cleaning means:

• Water can circulate freely
• UV and ozone can work efficiently
• The hardware lasts longer
• Water quality stays consistent

Lifespan and benefits of the Canadian Spa Glacier Filter

A quality Canadian Spa hot tub filter can technically be used for up to twelve months with regular cleaning. For best water care, however, we recommend swapping the Glacier Filter every six months — the antimicrobial properties fade after that point.

Depending on use, an earlier swap can make sense. If your hot tub gets heavy or shared use, replacing the filter every three to four months is a sensible move to keep filtration consistent and the antimicrobial technology fully effective.

The Glacier Filter combines high-quality materials with silver-ion technology and offers some real advantages for clean, hygienic water.

Key benefits of the Glacier Filter

• Antimicrobial layer that actively works against bacteria
• Silver-ion infused plastic that inhibits bacterial growth
• Cleaner spa water through extra microbiological control
• Reemay® filter medium from the USA with antimicrobial protection
• Easy-to-clean pleats that make routine cleaning simpler

The integrated silver ions act in a similar way to chlorine, but without the chlorine smell or extra chemical load. They inhibit microorganisms directly within the filter material, supporting long-term water care. (Silver has actually been used to preserve water since ancient times — the same antimicrobial property is now being put to work in modern spa filters.)

Worth knowing:

• After six months the Glacier Filter loses its antimicrobial protection
• For optimal filtration, swap every six months
• With careful upkeep, up to twelve months is possible

Replacing the filter on time keeps filtration consistent, water quality higher and your hot tub hardware better protected.

The filter cleaning brush — a practical helper

The Canadian Spa Filter Cleaning Brush is a useful piece of kit for thorough filter cleaning. Unlike a basic garden hose, the brush spreads the water through several built-in fan jets, so the spray can be guided cleanly between the pleats.

Benefits of the filter cleaning brush:

• Ten built-in fan jets
• Even water distribution
• Rotary control for water pressure
• Removable brush head
• Straightforward to use

With the brush, even deep-seated dirt comes out far more easily.

Important: don't use chemicals, household cleaners or solvents — they can damage the filter and may affect the warranty.

Day-to-day use

Using it is simple and slots easily into a regular maintenance routine:

• Take the filter out of the hot tub
• Connect the brush to your garden hose
• Set the water pressure
• Work systematically through each pleat
• Let the filter dry completely before refitting

The whole process takes only a few minutes and should be done every one to two weeks.

The brush isn't just for hot tub filters — it works equally well on:

• Pool filters
• Swim spa filters
• Commercial spa systems

Water care as part of your wellness routine

A hot tub is about comfort and quality of life. To keep the experience consistent, water care really needs to sit alongside the rest of your routine. A clean filter means:

• Clearer water
• Lower energy use
• Less chemistry needed
• More stable readings
• Longer life for the components

The combination of filtration, UV, ozone and regular filter cleaning creates a balance you'll notice straight away.

Wrapping up

Hot tub water care is a system. The filter is the foundation everything else builds on — only with a clean, working filter can UV and ozone really do their bit. Regular filter cleaning, paired with a timely filter swap, is what keeps everything efficient and the water consistently good.

Available on our UK website:

• Canadian Spa Filter Cleaning Brush — view product
• Canadian Spa Glacier Filter — view product
• Canadian Spa Filter Cleaner — view product

Invest in steady upkeep and quality components, and you'll get clearer water and easier maintenance for the long haul.

How each part of the system works

System	How it works	What it does not do
Filter	Water is drawn through pleated fabric that physically traps particles, oils and debris	It does not kill bacteria on its own
Ozone	An ozonator turns oxygen in a stream of air into ozone, which is drawn into the water and breaks down organic contaminants	It does not leave a lasting sanitiser in the water, so you still need chlorine or bromine
UV	Water passes a UV lamp, which damages the DNA of microorganisms passing close to it	It only treats water as it flows past the lamp, so it does not sanitise the whole tub
Sanitiser	Chlorine or bromine stays in the water and keeps working between filter cycles	It works poorly if pH and alkalinity are out of range

Each one covers a gap in the others, which is why they work best together.

Combined maintenance schedule

How often	Job
Before each soak	Quick look at the water; shower before getting in
2 to 3 times a week	Test with test strips and adjust: alkalinity, then pH, then sanitiser
Weekly	Shock the water, check the water level, skim out debris
Every 2 to 3 weeks	Rinse the filter with a hose
Every 3 months	Drain and refill; soak the filter overnight in Filter Cleaner
Every 6 months	Replace a Glacier filter for best performance (up to 12 months for economy, sooner with heavy use)
Yearly	A service visit to check pumps, heater and ozone

If your spa has a UV system, check the owner's manual for the lamp replacement interval for your model.

Signs one part of the system needs attention

• Cloudy water with balanced chemistry: often the filter. Clean or replace it.
• Sanitiser used up very quickly: heavy use, or the ozone may not be working. Shock the water and ask us to check the ozonator at your next service.
• Strong chemical smell: used-up chlorine. Shock the water with the cover open.
• Weak jets and slow heating: a blocked filter restricting flow.

Frequently asked questions

Can I stop using chlorine if I have ozone and UV?

No. Ozone and UV reduce how much sanitiser you need, but a measured level of chlorine or bromine is still needed to keep the water safe.

How do I know the ozonator is working?

You may see fine bubbles at one jet during filter cycles on some models. If you are unsure, ask the technician to check it at your next service.

Does a cleaner filter really save energy?

A clean filter lets water flow freely, so the pump works less hard and the heater gets the flow it needs.

Which filter does my spa take?

Check your model in our filters collection, or see our guide on when to replace your hot tub filter.