Year one of cold plunging, I spent close to $800 on accessories. Some of it was smart. Most of it was not. There was the fancy floating thermometer that sat on the surface and lied to me every single morning. The ozone generator I bought before understanding that ozone needs a sanitizer partner. The “insulated” cover that was really just a vinyl sheet with a foam sticker on top.
I got results from the plunging itself by week two. The accessories situation took much longer to sort out.
This guide is organized differently than most. Instead of listing products, it is organized by the problem each accessory solves. If you do not have that problem yet, you do not need that product yet. Start with the basics, see what actually annoys you, then layer in solutions.
The Basics You Actually Need
There are three things that will improve every single session: a thermometer, a cover, and a non-slip mat. Everything else is optional depending on your setup.
Thermometer: You Need One More Than You Think
The first thing most people skip is a dedicated thermometer. The reasoning goes: the water is cold, I can tell it is cold. That is good enough.
It is not good enough.
Cold water at 55°F and cold water at 45°F feel the same for the first five seconds. They are not the same physiologically. At 55°F you are getting meaningful cold stress response. At 45°F you are compressing the timeline significantly and increasing risk if you are new to this. At 65°F you are barely doing anything. You need numbers, not vibes.
The best affordable option available right now is the Inkbird IBS-TH2, which runs $12 to $15 on Amazon. Specifications: measures -40°F to 140°F, accurate to ±0.5°F at cold temps, IPX4 waterproof rating (splash-resistant, not submersible), Bluetooth range of 98 feet, and runs on 2 AAA batteries for 3 to 6 months.
The Bluetooth feature is more useful than it sounds. You can check your plunge temp from inside the house before you go out and realize it has already warmed up to 62°F. The app (Inkbird) also logs historical data, which helps if you are tracking protocol changes over time.
One thing almost nobody covers about thermometer placement: where you put the probe matters more than the thermometer itself. Surface readings can run up to 10°F warmer than mid-depth readings in still water. This is because cold water sinks and stratifies. If your probe is floating at the top, you are reading the warm layer, not the temperature you will actually be immersed in.
Place the Inkbird probe 12 to 18 inches below the surface, secured to the side of the tub with a small clip or suction cup mount. That is your real water temp. The IBS-TH2 unit itself should stay out of the water, clipped to the edge. IPX4 handles splashes fine but do not submerge the main unit.
Cover: The Single Biggest Temperature Variable
The most expensive mistake I made was not buying a cover in the first month. Without a cover, a cold plunge loses up to 40% of its cold through the water surface. In a 70°F ambient environment, that means 10 to 15°F of temperature rise every single day.
At $10 to $30 per session worth of ice, that is a problem you should solve before you solve anything else.
The simplest solution is a foam pool solar cover cut to fit your tub. Covers rated R-10 or higher cut daily temperature rise from that 10 to 15°F down to 4 to 6°F. That is more than 50% reduction in ice use or chiller runtime for no complicated installation.
You do not need a custom-fitted insulated cover unless you live somewhere extremely hot or are using a chiller and want to maximize efficiency. For most setups, a $25 foam solar cover from a pool supply store, cut to size with scissors, does the job. The blue bubble-wrap style pool covers that cost $20 to $30 achieve R-4 to R-6, which is adequate for most climates.
If you want serious insulation, XPS foam board (the pink or blue rigid foam at home improvement stores) cut to fit the tub opening gets you R-10 for about $15 to $20 worth of material. Put a sheet of it on top after each session and you will notice the temperature drift slow down significantly.
Non-Slip Mat: A Safety Item, Not a Comfort Item
I added this one after slipping on the deck next to my tub for the third time. Wet feet, wet deck, cold morning, insufficient attention. The slip happened getting out, not going in.
Get a rubber bath mat with suction cups rated for wet surfaces. The Yimobra mats (34.5″ x 15.5″, around $18 on Amazon) have 253 suction cups on the underside and hold on smooth surfaces reliably. The mat sits outside the tub, not in it, so you step onto it when you exit.
Size matters: get one at least 34 inches long so both feet land on it when you step out. If your tub sits on a wood deck or textured concrete, a mat with drainage holes keeps it from pooling water underneath, which extends the life of both the mat and the deck surface.
Keeping the Water Clean Without a $3,000 Chiller
Water chemistry is the section that every cold plunge accessory guide skips, yet it is the number one practical problem for people who keep a filled tub year-round.
Without any treatment, cold plunge water turns visibly cloudy and starts growing bacteria within 5 to 7 days of regular use. At that point you are dumping and refilling, which wastes water and time. The goal is to extend water life to 3 to 4 weeks between full changes.
The four main approaches are chlorine, bromine, ozone, and saltwater. Here is an honest assessment of each.
Chlorine: Works Warm, Not Cold
Chlorine is what most people reach for because it is what they know from pools and hot tubs. In cold water, it is the wrong choice.
Chlorine effectiveness drops sharply below 65°F. At a typical 50 to 55°F plunge temperature, you would need to maintain 8ppm or higher to achieve proper sanitization. The CDC recommends a maximum of 4ppm in drinking water. You would be sitting in a concentration that exceeds safe limits while your skin absorbs it for 5 to 10 minutes at a time.
That is not a trade-off worth making. Skip chlorine for cold plunge applications.
Bromine: The Right Chemical for Cold Water
Bromine is less pH-sensitive than chlorine and maintains its effectiveness at temperatures well below 65°F. A maintained level of 3 to 5ppm in a cold plunge is both effective and not irritating to most people.
The pros: low odor (nothing like chlorine smell), works properly in cold water, requires less frequent dosing, and the tablets are easy to manage with a floating dispenser.
The con: bromine costs more per pound than chlorine and requires about a week to build up a proper bromide reserve in fresh water when you first start. You will also want a simple test strip kit to check levels once or twice a week.
For a 100 to 150-gallon cold plunge, bromine tablets in a floating dispenser is the easiest chemical setup. Start with a half-load in the dispenser, test after 24 hours, and adjust from there. Once balanced, a single dispenser load lasts 1 to 2 weeks.
This is what I use now. It took about 10 days to dial in but I have not had a water quality issue in months.
Ozone: Powerful But Needs a Partner
Ozone is the most potent disinfectant option available for cold plunge use. It is twice as effective as chlorine and works extremely well in cold water, which is actually where it lasts longest. In warm water, ozone dissipates quickly. In cold water, it persists.
Here is what most ozone guides miss: ozone provides no residual protection. The moment the generator stops running, any protection it provided begins fading. If bacteria enter the water after the generator cycles off, there is nothing to stop them.
This means ozone must be paired with a low-level residual sanitizer, either bromine or a minimal chlorine dose. Used together, ozone handles the heavy lifting and the bromine mops up the rest.
A quality ozone generator for a home cold plunge runs $80 to $150 on Amazon. It is a worthwhile upgrade if you are plunging daily and want to reduce chemical use. Unnecessary if you are plunging three to four times per week and bromine maintenance is working fine.
Saltwater: Low Chemical Feel, Higher Complexity
Saltwater systems are popular with commercial cold plunges and some premium home units. They convert salt into chlorine automatically.
The salt concentration in these systems (around 3,000ppm vs. ocean water at 35,000ppm) means most people notice the water feels softer than chemically treated water. Less hands-on chemical handling is a genuine quality-of-life improvement.
The con: a saltwater chlorinator adds $200 to $500 to your setup, and in very cold water below 50°F, the chlorine conversion rate from salt can become inconsistent, requiring manual adjustments. This setup works better for chiller systems maintaining 50 to 60°F than for ice-based setups that regularly hit 40°F.
The Simplest Effective Setup
For most people: bromine tablets in a floating dispenser ($15 for a starter kit), a pack of test strips ($8), and a full water change every 3 to 4 weeks. That is it. You will spend about $10 to $15 per month on chemical maintenance instead of dumping and refilling every week.
Temperature Control Without Spending More Than the Tub
Here is the honest math on getting and keeping cold water.
Ice: The Real Cost Nobody Discusses
Ice gets expensive fast. A 100 to 150-gallon cold plunge to 50°F in summer conditions takes 40 to 80 pounds of ice depending on ambient temperature and starting water temp. At $1 to $2 per pound from a gas station or grocery store bag ice, that is $40 to $80 per session in summer.
Even at a dedicated ice supplier where bulk ice runs $0.25 to $0.50 per pound, you are at $10 to $40 per session. At $10 per session three times per week, that is $1,560 per year just in ice. Daily users spending $10 per session hit $3,650 per year.
That math rarely appears in cold plunge content because the people writing it are selling tubs, not ice.
Chillers: The Better Long-Term Math
A quality chiller for a home cold plunge runs $1,000 to $3,000 for a unit that maintains 50°F. Full chiller-equipped cold plunge tubs with filtration from brands like Redwood Outdoors run $3,000 to $7,000.
Electricity cost to run a chiller is approximately $1.50 to $3 per day, or $550 to $1,100 per year. For daily users, that is the break-even point compared to ice within 18 to 36 months depending on setup cost.
The non-financial argument for a chiller: you will plunge more consistently. The friction of buying ice, hauling it, and timing sessions around ice supply causes most people to skip sessions. Remove the friction and the habit sticks. Consistency is the entire point.
Chiller Alternatives: What Actually Works
If you do not want to spend $1,000 on a chiller yet, two approaches are worth trying.
Pre-cooling the water: Fill the tub with cold tap water the night before. In winter months, tap water in many regions runs 45 to 55°F and may need zero ice at all. Fill overnight and check the temperature in the morning before committing to a session.
Portable chiller add-ons: Water chillers that attach to an existing tub via hose fittings run $800 to $1,500. These do not cool as fast as purpose-built cold plunge systems, but they maintain temperature overnight and reduce ice dependence significantly. Hydroponic chillers (Active Aqua and similar brands) repurposed for cold plunge use are popular in DIY setups and work well for anyone willing to do the research on flow rates.
What I Bought That I Regret
This is the year-one list.
Fancy floating thermometer ($35): It floated on the surface and read the warmest water in the tub. Off by 8°F compared to my actual plunge temperature every time. The Inkbird IBS-TH2 at $14 is more accurate, connects to my phone, and stays out of the way when I am in the water.
“Cold therapy” bath salts ($40): These are marketing. Epsom salts with blue dye and mint fragrance. The magnesium absorption claim is not supported by evidence for cold water immersion specifically, and the dye sits in your water and creates extra filtration work. Not worth it.
Compression recovery boots ($180 in a combo bundle): Included with a “cold plunge starter kit.” The boots are fine for post-workout recovery but have nothing to do with cold plunging itself. Bundled products are almost always a signal someone is padding margin. Buy things individually when you know you need them.
Floating UV sanitizer ($65): A floating UV unit marketed as circulating and killing bacteria. The problem: it is too small to move a 100-gallon tub’s water meaningfully, and UV alone provides zero residual protection. I replaced this approach with bromine tablets and have not thought about it since.
Insulated vinyl cover ($55): A vinyl sheet with thin foam laminated to the underside. Looked professional in the product photos, performed like a beach towel. After three weeks the foam started delaminating at the edges from moisture. I replaced it with $25 of XPS foam board cut to size.
What I Wish I Had Bought Sooner
A dedicated kitchen timer ($10): This is a safety item for new users, not a convenience. I did not use a timer my first two months because I thought I could judge time while plunging. You cannot. Cold water alters your perception of time significantly. Minutes feel like either 30 seconds or an hour depending on your breath control and stress level that day.
For beginners: limit sessions to 2 minutes maximum. Even for experienced plungers, 10 minutes is a hard ceiling for temps below 55°F. Core body temperature begins dropping meaningfully after 7 to 10 minutes in 50°F water for most adults. When the timer rings, get out. Not in a minute. Out.
Buy a cheap mechanical kitchen timer. Hang it on the side of the tub. Set it every single time. The ones with a simple turn-dial cost $8 to $12, require no batteries, and are visible from inside the tub.
A water testing kit ($8): Test strips that check bromine and pH. Without these, you are guessing at your chemistry maintenance. Testing twice a week takes 30 seconds. Neglecting this for two months led me to discover my water was both over-brominated and low pH at the same time. It irritated my eyes for three days before I figured out what was wrong. The kit costs $8.
A silicone grip mat for inside the tub ($15): Different from the deck mat. This one goes on the floor inside the tub so your feet do not slide when you lower yourself in. Cold water plus smooth fiberglass or plastic tub floor plus wet skin is a slip risk at the worst possible moment. A silicone shower mat with suction cups solves this completely.
A towel hook within arm’s reach of the exit ($12): When you exit a cold plunge at 50°F, your hands are not working at full capability. Fumbling for a towel that is five feet away is uncomfortable in a way that is hard to describe until you have experienced it. A simple adhesive hook-and-loop mount on the nearest wall keeps your towel within reach. Dry off before you do anything else.
Full Accessories List by Budget
$50 to $65: The Non-Negotiables
If you are getting started and want to spend the minimum to do this right, this is the list:
- Inkbird IBS-TH2 thermometer ($14): Bluetooth, -40°F to 140°F range, accurate to ±0.5°F, IPX4 splash-resistant, 98-foot Bluetooth range. Place probe at 12 to 18 inch depth.
- Mechanical kitchen timer ($10): Safety. Set it every session without exception.
- Foam solar cover cut to fit ($25): Slows temperature rise by more than 50%. Gets you more sessions per bag of ice.
- Yimobra non-slip bath mat, 34.5″ x 15.5″ ($18): 253 suction cups. Place outside the tub on your exit side.
These four items address the four most common problems: not knowing your real temp, staying in too long, water warming too fast, and slipping on exit.
$150: Add Water Chemistry and Safety Grip
Add to the $65 list:
- Bromine tablet starter kit with floating dispenser ($20): 1 lb tablets, floater, and test strips in one package.
- Water testing strips, 50-count ($8): pH and bromine. Test twice per week.
- Silicone bath mat for inside the tub ($15): Suction cup grip for tub floor. Prevents slips during entry and exit inside the water.
- Small submersible circulation pump ($30): Keeps water from stratifying and helps chemicals distribute evenly. Run it for 15 minutes after adding chemicals.
At this level, you have consistent temperature readings, safe session timing, basic water chemistry under control, and proper grip for entry and exit.
$300 and Up: Temperature Control Upgrades
Add to the $150 setup:
- Ozone generator, 100 to 500mg/hr output ($80 to $120): Pair with low-level bromine maintenance. Extends water change intervals to 4 to 6 weeks and reduces chemical use.
- XPS foam board insulated lid, custom-cut ($25 to $40 for two 2-inch panels): Achieves R-10 insulation, reduces daily temperature rise to 4 to 6°F. Cut two panels to size and stack them for maximum insulation.
- Inkbird IBS-TH2 Plus with external probe ($22): The Plus version has a wired external probe. Keep the unit outside the tub entirely and run the probe to 15-inch depth. More accurate and better for long-term electronics protection.
At $300 total, you have addressed water quality, temperature maintenance, and monitoring in a way that supports a 5 to 7 session per week practice without constant ice purchases or water changes.
One More Thing
The biggest improvement I made to my whole cold plunge setup had nothing to do with accessories. I moved the tub 12 feet closer to the back door. Friction is the enemy of consistency. If the process from deciding to plunge to being in the water takes under 90 seconds, you will do it. If it is a four-minute ordeal involving ice, cover removal, mat setup, and digging gear out of an outdoor shed, you will skip it.
Get the basics right. Keep it accessible. The accessories matter less than you think. The habit is the whole thing.
