How to Clean a Hot Tub

Filters remove hair, skin, body oils and debris from the water, and they clog quickly. Every week (or after heavy use), switch the hot tub off at the mains, lift out the filter cartridges and rinse them with a hose, working the spray between the pleats from top to bottom. Don't use a pressure washer, which can damage the pleats.

Every month or so, soak the filters overnight in a filter cleaning solution to dissolve oils and scale, then rinse thoroughly. Many owners keep a second set of filters so one can soak while the other is in use. Replace filters every 12–24 months, or when the pleats are damaged or they no longer come clean.

Test the water regularly – several times a week for a tub in use – and keep the sanitiser (chlorine or bromine) and pH within the ranges the manufacturer recommends. Shower before getting in, avoid using the tub with sun cream or make-up on, and keep the cover on when the tub isn't in use.

Cloudy, foamy or smelly water usually means the sanitiser level is low, the filters are dirty, or the water has simply been in use too long. Getting the chemistry right is a specialist topic; your hot tub supplier's guidance is the best starting point.

Most hot tubs need draining and refilling every three months or so, depending on use and the size of the tub. Before draining, use a pipe cleaning (line flush) product according to its instructions – you add it to the water and run the jets, and it lifts biofilm from inside the pipework that you can't otherwise reach. You may see a scummy layer appear on the water as it works.

Switch off at the mains, drain the tub following the manufacturer's instructions, and remove the filters for a deep soak.

With the tub empty, wipe the acrylic shell with a hot tub surface cleaner or a solution of white vinegar and water on a soft sponge, paying attention to the waterline where a ring of scum forms. Use an old toothbrush around the jets, headrests and the filter housing. Rinse thoroughly so no cleaner is left to foam up when you refill.

Avoid household cleaners, bleach, abrasive creams and scourers – they can damage the acrylic and upset the water chemistry when you refill.

The cover keeps heat in and debris out, but its underside sits above warm water and can grow mildew. Every month, wipe the top with a mild soap solution or a cover cleaner and rinse, then wipe the underside and let it air before replacing it. A vinyl conditioner a few times a year stops the cover cracking in the sun.

A cover that feels very heavy has probably absorbed water into its foam core and won't insulate properly. It may need replacing.

Brush leaves and debris away from the hot tub regularly. Clean a wood or composite cabinet with a soft brush and mild soapy water, and treat timber cabinets with a suitable protective oil occasionally. Keep the surrounding decking or patio clean and free of algae, which makes it slippery – see our guides to cleaning decking and cleaning a patio.

Holiday let owners usually need the hot tub drained, cleaned and refilled between guests, or at least the water tested, treated and logged before each new arrival. This is normally a specialist job: some holiday let cleaning companies offer hot tub servicing, while others work alongside a hot tub technician. If you're booking changeover cleaning, make sure the quote says who is responsible for the hot tub and how it's recorded.