The Comprehensive Guide to Hot Tub Maintenance
Looking after a hot tub is mostly about a few regular habits: testing the water, cleaning the filters and noticing when something changes. Once you understand what your particular model needs, those jobs become a familiar part of owning it.
This guide covers everyday water care, cleaning, seasonal checks and common problems. Your owner's manual should always take priority over general advice, particularly if you have a salt system or other specialist water-care equipment.
Understanding Water Chemistry
Clear water is reassuring, but appearance alone cannot tell you whether it is safe to use. Testing tells you whether there is enough sanitiser and whether the water is balanced. Both matter for bathing comfort and for protecting the heater, seals and other components.
- pH: Most hot tubs require a pH between 7.2 and 7.8. Low pH makes the water acidic, which can cause corrosion and irritation. High pH can encourage scale and reduce chlorine's effectiveness. Use suitable test strips or a water-testing kit, and follow the instructions when adjusting it.
- Total alkalinity: This helps keep pH steady. If it is too low, pH can fluctuate; if it is too high, pH can be difficult to bring down. The correct range depends on your hot tub and water-care system, so check your manual rather than relying on a universal target.
- Sanitiser: Chlorine and bromine are commonly used to control bacteria, but the product and target level must suit your hot tub. A salt system generates chlorine from salt, so it still needs a measurable chlorine level and regular checks. Mineral systems may support sanitisation, but should not be treated as a replacement for the sanitiser their instructions require.
- Calcium hardness: Too much calcium can cause scale, but the right level varies considerably between systems. For example, the FreshWater Salt System requires a lower calcium hardness than many conventional hot tubs. Check the manufacturer's specified range before adding a hardness increaser or using softened water.
Test before bathing and at the intervals recommended for your system, with extra checks after heavy use. Automated monitoring can make water care easier, but you still need to carry out the checks specified by the manufacturer.
Measure doses carefully, allow the recommended circulation time and retest before making further adjustments. Never mix chemical products together, and follow each product's instructions for adding it to the water. Wait until readings are within the recommended ranges before using the hot tub.
If you use bromine granules, see our guide to the changes affecting bromine products for advice on your next steps.
Routine Cleaning and Maintenance
Filter Care
Filters collect debris, oils and other material that would otherwise remain in the water. As they become dirty, water flow can fall, affecting filtration, heating and jet performance.
Check them regularly and rinse away loose debris with a garden hose, usually every couple of weeks or more often if the hot tub gets heavy use. Avoid pressure washers, which can damage the filter material. Use a suitable filter cleaner for a deeper clean, following its instructions for soaking and rinsing.
A monthly deep clean is a useful starting point, but follow the schedule for your particular filter. Replacement intervals also vary: damaged material, deteriorating end caps or a filter that no longer cleans properly are reasons to replace it.
Switch off the hot tub as directed in the manual before removing filters, and refit them correctly before restarting it.
Managing Hard Water
Hard water is familiar to many Oxfordshire homeowners. The concern for a hot tub is scale forming on surfaces and equipment, particularly when calcium hardness and pH are too high.
Test the fill water and ask your supplier which treatment suits your system. An ordinary hose pre-filter does not necessarily remove dissolved calcium, and a scale-control product does not lower calcium hardness. Some systems need a specific calcium-removal treatment or an approved water-softening method.
Cleaning the Shell and Waterline
Wipe the waterline regularly to remove the residue left by body oils, cosmetics and other contaminants. Use a soft cloth and a cleaner approved for hot tub surfaces. Household detergents and abrasive products can damage finishes or leave residues that cause foaming.
When the hot tub is empty for a water change, clean the rest of the shell and rinse away any cleaning product before refilling.
Draining and Refilling
Over time, substances build up in the water that filtration cannot remove. If it becomes increasingly difficult to keep the water balanced, a water change may be due.
Many conventional hot tubs need draining and refilling roughly every three to four months, depending on use. Some salt systems allow longer intervals under the right conditions, so follow your system's guidance rather than changing the water by the calendar alone.
Use a compatible plumbing cleaner when recommended, following its instructions before draining. Switch off the power before emptying the hot tub, follow local guidance for disposing of treated water and refill using the method in your manual to reduce the risk of an airlock. Balance and sanitise the fresh water before bathing.
Looking After the Cover
A well-fitting cover keeps debris out and limits heat loss. Clean it with products suitable for its material, and use a protectant only if the manufacturer recommends one.
Check the seams, hinges, straps and locks, and make sure the cover closes properly. If it becomes unusually heavy, its insulation may be waterlogged. Tears, poor fit and damaged insulation can all affect how well it retains heat.
A cover lifter makes opening and closing easier and helps keep the cover off the ground. Keep the cover secured when the hot tub is not in use.
Seasonal Care
Using Your Hot Tub in Winter
A hot tub designed for year-round outdoor use can stay running through winter. Keep the water at the correct level, maintain water quality and check that heating and circulation are working. A sound, properly fitted cover helps limit heat loss.
Pay particular attention after a power cut or if an error message appears. Freeze protection depends on the equipment being able to operate, so a hot tub that has stopped heating or circulating needs prompt attention in freezing weather.
If you want to shut it down for an extended period, draining the shell alone is not enough. Water can remain in pumps, pipework and other components, where freezing can cause expensive damage. Follow the manufacturer's winterisation procedure or arrange professional winterisation. Do not add antifreeze unless the manufacturer specifically instructs you to use an approved product.
Summer Water Care
Warmer weather often brings more use, which can increase sanitiser demand. Test accordingly, particularly after several people have bathed, and keep the cover closed when the hot tub is not in use.
Do not add chlorine stabiliser simply because it is summer. Some chlorine products already contain it, and excessive levels can make water care more difficult. Follow the advice for your sanitiser and system.
A quick shower before bathing helps reduce the amount of sweat, cosmetics and other residue entering the water throughout the year.
Common Hot Tub Problems and What to Check
Start with the basics: water level, test results, filter condition and any message on the control panel. If the water is discoloured or cloudy, or the sanitiser is outside its recommended range, leave bathing until the cause has been addressed.
Cloudy Water
Cloudiness can come from insufficient sanitiser, poor filtration, unbalanced water or accumulated contaminants. Test the water, check the filtration settings and clean the filters. If a reading is outside the recommended range, correct it according to your water-care instructions.
A compatible clarifier may help with fine particles, but it will not disinfect the water or solve an underlying filtration problem. If cloudiness persists, seek advice rather than repeatedly adding products.
Watch our one-minute guide to cloudy water.
Foamy Water
Persistent foam often comes from detergent in swimwear, body-care products or a build-up of contaminants. Check water balance and filter condition, and rinse swimwear thoroughly without fabric conditioner.
A foam reducer can temporarily suppress the foam, but it does not remove what caused it. Follow your system's guidance on oxidising treatments, and consider a water change if the problem continues. Do not add a large dose of sanitiser without checking the readings and product instructions first.
Watch our one-minute guide to foamy water.
Green Water
Green water needs investigating before you use the hot tub. Low sanitiser can allow microbial growth, but dissolved metals can also give water a green tint. Colour alone does not identify the cause.
Test the sanitiser and pH, check the filters and seek advice if the cause is unclear or the colour remains after correcting the readings. The right treatment depends on what is causing the problem.
Watch our one-minute guide to green water.
The Hot Tub Is Not Heating
Check the set temperature and operating mode first. Economy or sleep settings may limit when heating occurs. A recent refill will also take time to reach bathing temperature.
Check the water level, filters and display for any error message. Restricted flow can prevent heating, but heater, sensor and pump faults need professional diagnosis. Do not open electrical equipment or repeatedly reset a tripping supply.
Weak Jets
Before assuming a pump fault, check whether the jets are open and whether a diverter control is directing water elsewhere. Low water level and dirty filters can also affect performance.
If the problem began after refilling, an airlock may be involved. Follow the troubleshooting steps in your manual rather than loosening plumbing connections yourself. Persistent weak flow or unusual pump noises need further investigation.
Error Messages
Make a note of the exact code or take a photograph, then check the manual for your model. The same code can mean different things on different systems.
If the message returns after the recommended checks, contact your supplier with the code and a description of what the hot tub is doing. This gives the engineer a useful starting point.
Unusual Noises or Leaks
A new grinding, rattling or persistent humming noise deserves attention, particularly if flow has changed. Likewise, an unexplained drop in water level or water around the cabinet may indicate a leak.
Arrange advice promptly. If you suspect an electrical fault, notice a burning smell or find water near electrical equipment, switch the hot tub off at its isolator if it is safe to do so and seek professional help.
When Professional Servicing Helps
Day-to-day water care and professional servicing do different jobs. Regular testing and cleaning keep the hot tub ready to use; a service provides an opportunity to clean more thoroughly and inspect equipment that owners would not normally access.
An annual service is a useful part of many owners' maintenance routine. The work included varies by provider and package, so check what is covered. Servicing can identify wear, leaks and developing faults, but it does not replace the water care needed between visits.
At Hot Tubs Oxfordshire, aftercare is part of how we look after the people who buy from us. We also offer Maintenance Plans for eligible hot tubs following an assessment. As our engineers become familiar with the spa, plan membership provides access to callouts and repairs as well as scheduled maintenance.
If your hot tub came from another supplier, tell us its make, model and history when enquiring so we can explain the support available. If we cannot help with your particular model, its original supplier or an authorised dealer for the brand is a sensible place to start.
Keeping Your Hot Tub in Good Condition
The habits that protect water quality also help protect the equipment: keeping readings within the correct ranges, maintaining clean filters and dealing with changes before they become persistent problems.
You do not need to dismantle pumps, lubricate motors or descale a heater yourself. Those tasks, where appropriate, belong with a qualified technician. Your role is to follow the owner's maintenance schedule and report anything unusual.
For energy use, start with the cover, operating settings and filtration schedule recommended for your model. Keep the cover closed between uses and have damaged insulation or equipment faults assessed. Changes to pumps, heaters or controls should be discussed with the manufacturer or an authorised technician.
A hot tub should be somewhere you can relax. A manageable care routine, the right products and help when you need it make that much easier. If you are unsure about a test result or a change in how yours is behaving, ask before guessing at a treatment.
Manufacturer guidance: For Hot Spring models, consult the owner's manual for your hot tub and water-care system.
