Cold plunge accessories worth buying in the UK (2026), and the ones owners never mention

Updated 4 October 2026: Amazon UK prices and ratings were read again on 4 October. They change often, and the price on Amazon is the one that counts. Since 29 September the lid advice has noted that Lumi Therapy Ltd is in administration. Published 23 September 2026.

Plungepedia read 1,202 Reddit posts and comments from cold plunge owners and counted what they talk about. Pumps came up 162 times, filters 133, hoses and fittings 91, ozone and UV 71, sanitisers 53 and lids 41. Thermometers came up 7 times, ice makers twice and changing robes not once. Owners spend their time keeping the water clean and the plumbing working, so that is where this guide spends its time too.

Written by Aodhan, who has owned six cold plunges in three years. Amazon links on this page are affiliate links: Amazon pays us a small commission and you pay the same price. We have not tested these products ourselves; the picks come from what owners discuss, the specifications, and each listing's rating and number of ratings.

If you only buy three things

1. A proper insulated lid, if your tub did not come with one.
2. A floating thermometer, so you know what you are actually sitting in.
3. Spare filter cartridges in the right size for your chiller.

Everything below is either a way to make those three work better or something you can live without.

The lid comes first

It is the cheapest running-cost saving there is. On our running costs model, an uninsulated 450 litre tub in summer shade costs about £27 a month with a lid and £37 without one, and the lid also keeps out leaves, insects and the light that feeds algae.

The catch is that most "ice bath covers" on Amazon UK are not insulated at all. Search for one and the first page is full of Oxford-fabric drawstring covers at £6 to £15: they keep the rain out and do very little for the temperature. If your tub's maker sells an insulated lid for your model, buy that one, because it will fit (Lumi's Thermo Lid for its 75 cm pods, for example, has been listed on Amazon UK; Lumi Therapy Ltd has been in administration since August 2025, the Lumi shop is now run by a separate company, and recent Trustpilot reviewers say messages often go unanswered, so check who the Amazon seller is and its returns window before you order). For a stock tank, the COSFUN cover for 100 gallon oval tanks has the most ratings of the tank covers (4.6 stars from 195 ratings, £23.03 at Amazon UK); treat it as a weather cover and lay a foam board under it if you want real insulation.

Filters: boring, and the thing owners ask about most

Every chiller pulls water through a cartridge, and a clogged one makes the pump strain and the compressor run longer. Most UK chillers take a pleated cartridge around 12.7 cm by 6.35 cm (5 by 2.5 inches); check yours before you order, because the fittings differ even where the sizes match.

Rinse the cartridge with a hose every week or two and swap it when rinsing no longer brings the flow back. On r/coldplunge, owners using cheap 5-inch cartridges report them lasting up to a season, and the ones who shower before getting in get the longest out of them.

Treating the water

This is where owners disagree most, and where the product claims are loudest. Three approaches come up again and again.

Hydrogen peroxide is the favourite on Reddit because it breaks down into water and oxygen and does not smell. The 3% bottles on Amazon UK (Monicare's 250 ml has 4.4 stars from 4,728 ratings) are sold as household cleaners and are small for a 400 litre tub, so owners who use peroxide seriously buy a spa-strength product and dose to the maker's instructions for their volume. Either way, buy test strips: the Bartovation 0 to 100 ppm strips (4.6 stars from 465 ratings, £24.39 at Amazon UK) are the most-rated. Guessing the dose is how people end up with cloudy water or itchy skin.

Chlorine tablets in a floating dispenser are the cheap, familiar option. Aqua Pristine's ice bath tablets (£18.99 at Amazon UK, 4.3 stars from 106 ratings) are UK-made and sold for ice baths as well as hot tubs. Chlorine works more slowly in cold water, so follow a cold-water dose where the product gives one, not the hot tub dose.

Purpose-made treatments such as Bio Ouster's 3-in-1 for cold plunges (£48.86 at Amazon UK, 4.5 stars from 543 ratings) or eco3spa's chlorine-free starter kit, which is sold for hot tubs (£48.95 at Amazon UK), are simpler to dose and cost more per month.

Pick one and stick with it; mixing products is where the trouble starts. And whatever you use, a shower before you get in does more for the water than any bottle.

Ozone: have it built in, or leave it

Ozone and UV came up 71 times in the owner posts, usually as part of a chiller rather than a separate box. The add-on ozone units on Amazon UK are a mixed bag: the most-rated "ozone generators" in our search were air purifiers rated at 30,000 to 120,000 mg an hour, which are not for water, and ozone gas irritates the lungs. The water-rated bubblers sold for cold plunges have few ratings, and several average under 4 stars. If you want ozone, choose a chiller with it built in; the chiller guide shows which ones have it.

A thermometer that floats

A chiller's display reads the water where it enters the chiller, which is not always what is around your chest. A floating thermometer is the fix, and the cheap ones are fine. Intex's floating pool thermometer (£7.49 at Amazon UK, 4.4 stars from 4,444 ratings) has thousands of ratings behind it. If you want to see the temperature from the kitchen, OFFCUP's wireless floating thermometer with an indoor display costs £19.99 at Amazon UK (4.1 stars from 45 ratings). The "ice bath thermometer and timer" gadgets have noticeably lower ratings than plain pool thermometers.

An energy meter, and a favour to ask

A plug-in energy meter turns our running-cost estimates into your actual number. MECHEER's plug-in monitor has the most ratings of its kind (£11.88 at Amazon UK, 4.5 stars from 5,400 ratings). Check that any meter you buy is rated for a full 13 A, because the bigger chillers draw up to 1,800 W.

There is only one metered UK running-cost figure in public, and our model leans on it. If you meter your chiller for a month, email the kWh reading, your tub size and whether it has a lid to hello@plungepedia.com. We will add it to the running costs guide, with your permission.

Ice makers: the maths says no, mostly

Countertop ice makers collect a lot of ratings on Amazon UK. EUHOMY's has 4.3 stars from 24,376 ratings and ecozy's 12 kg model 4.4 stars from 5,557 ratings. The ratings are for drinks, though, and the numbers do not stretch to a cold plunge.

The machines in our search are rated at 12 to 14 kg of ice a day. Taking a 450 litre tub from a 15C summer tap to 8C needs about 44 kg once you allow for melting, so a machine running flat out makes one plunge's worth every three to four days. Scale the tub down and it starts to make sense: a 200 litre tub topped up from a 12C tap needs about 11 kg, roughly a day's output from something like the FOHERE 14 kg model (£59.99 at Amazon UK). For anything bigger, the running costs guide shows why a chiller works out cheaper within a summer.

Getting in and out safely

After a few minutes at 5C your feet are numb and your grip is poor, and the rim of an all-in-one or a barrel sits at thigh height or more. A step is a safety item, not a luxury. CosySpa's hot tub steps (£69.99 at Amazon UK, 4.5 stars from 107 ratings) are built for wet, outdoor use; for a lower tub, an anti-slip bath step such as the Crystals platform (£13.97 at Amazon UK, 4.6 stars from 578 ratings) is enough.

Inflatables and pods on a patio or deck benefit from a floor protector: it cushions the base, stops grit wearing through and adds a little insulation from cold paving. Lay-Z-Spa's 10-piece set (£35.04 at Amazon UK, 4.4 stars from 6,666 ratings) is the default choice.

And a changing robe, if you plunge outside in winter

Nobody on Reddit talks about them, but anyone who has walked back across a garden in January wet will understand why they sell. Winthome's towelling poncho (£25.99 at Amazon UK, 4.5 stars from 5,702 ratings) is the well-rated basic option; a waterproof sherpa-lined robe is the upgrade.

What we would not buy

• A chest freezer conversion. It is popular online, but it puts mains electricity and a person in the same box of water. We do not recommend it.
• An air ozone generator used anywhere near the tub.
• A thin fabric cover sold as "insulated". Check for a stated thickness or layers, or buy the tub maker's lid.
• Algaecide in water you sit in. Keep the lid on and the filter clean instead; algae needs light.

What accessories do I need for a cold plunge?

An insulated lid, a floating thermometer, spare filter cartridges if you have a chiller, and a water treatment you will actually use. A step and a floor mat are worth it for tall or inflatable tubs. Most other things sold as cold plunge accessories are optional.

Can a home ice maker keep an ice bath cold?

Not a full-size one. Countertop ice makers on Amazon UK are rated at 12 to 14 kg a day, and cooling a 450 litre tub from a 15C summer tap to 8C takes about 44 kg once melting losses are counted: three to four days of ice for one plunge. For a 200 litre tub topped up from a 12C tap it is about 11 kg, roughly a day's output.

What is the best way to keep ice bath water clean?

A lid, a quick rinse or shower before you get in, a filter that is rinsed weekly and changed on schedule, and one sanitiser used consistently with test strips to check it. Owners who do those four things report water lasting four to six weeks or more rather than a week.

Are ozone generators safe for an ice bath?

Only units built for water, fitted as the maker intends. The most-rated ozone generators in our Amazon UK search are air purifiers rated at 30,000 mg an hour or more, and ozone gas irritates the lungs. If you want ozone, the simplest route is a chiller with it built in.