5 things to look out for when buying a cold plunge for the first time

Pay attention to these so you don’t waste your money and time

Supertub 0.6
  • “HYDRAGUN has raised the bar with the Supertub... a premium experience at a fraction of the cost.”

  • “Best overall: the Supertub earns the top spot for its excellent temperature regulation and versatility.”

  • “Every feature and accessory that came with the Supertub really impressed us.”

    Hey cold plungers! We’re HYDRAGUN – a fitness/wellness tech company made up of a team of peak performance fanatics from around the world.

    We make recovery products trusted by Olympians, World Champions, NFL players, and other pro athletes and health and fitness professionals – including an ultra-quiet massage gun, a best-selling no-BS sauna blanket, and a heated knee massager beloved by runners and endurance athletes on four continents.

    Our latest release is the Supertub – which we designed to be the best-spec'd and best-value cold plunge on the market in 2024.

    Supertub cold plunge

    We equipped it with everything you need in a cold plunge – including these five things you should look out for when you’re buying one for the first time.

    1. Chiller horsepower

    This is the primary spec to look out for.

    It dictates how much cooling power your cold plunge has, so that it can get the water down to the freezing cold temperatures you want, and keep it there.

    Chillers on the market range from around 0.25 horsepower, up to 2hp or more.

    We recommend a 0.6hp chiller for those living in more temperate climates, and a 0.8hp chiller for those in hotter climates, like Singapore’s.

    Supertub cold plunge

    Any lower, and your chiller may struggle to keep the water cold, leaving you with warmed-up water and/or increasing the possibility of a breakdown.

    Conversely, if horsepower is too high, you’re paying a lot extra for not much added benefit.

    Contrary to popular belief, higher horsepower doesn’t make the water colder once you’re past a certain point. In fact, most high-quality true-to-specs cold plunges 0.6hp and higher can comfortably go down to 3-4°C regardless of horsepower.

    Chillers 1-2hp and higher are best suited for commercial use cases (e.g. if you’re running a very high-traffic gym or spa). But companies have started offering them to residential consumers as well, because they command higher prices (~S$7,000 and up).

    Supertub cold plunge

    The Supertub is priced at just S$4,999, with a compact yet powerful 0.8hp PermafrostTM chiller that’s strong enough to stand up to high-traffic situations like a plunge party or a full-day outdoor sporting event with 10-12+ plungers an hour.

    Supertub cold plunge

    We tested the water with a thermal camera and the lowest temperature reflected from the tub water was 1.2°C

    It also features over 25% less bulk than a comparable 1hp chiller, IPX4 water resistance for peace of mind, and an automatic power-saving mode that ensures it’s never drawing more power than it needs (electricity costs are just ~S$40-50 a month even if the chiller is left on 24/7).

    Supertub cold plunge

    2. Tub type

    Next we’ll look at the tub itself.

    There are three main materials on the market, and you can find the pros and cons of each below:

    As you can see, we found that inflatable tubs provide the best balance of performance, convenience and ease of handling, and durability overall.

    Performance. Steel tubs face multiple performance issues, so we recommend avoiding them if possible. They’re poorly insulated, so water in the tub will heat up faster when it gets warm, reducing the energy efficiency of your cold plunge. They also attract much more condensation than other materials, forming large drips and puddles outside and around the tub and encouraging mold, mildew, and water damage in the surrounding area.

    Ease of handling. During the lifetime of your cold plunge, you’ll need to change out the water, clean the tub, mop up spills and splashes, check the area around and underneath the tub for mold and mildew, and so on. We found during our long-term product testing process that a lightweight inflatable made maintenance a lot easier than a bulky hard-sided tub.

    Durability. Inflatables can be just as durable as hard-sided tubs if construction and materials are done right. For instance, we make the Supertub out of military-grade, double-walled marine vinyl – the same material military life rafts are made of. It’s tough, won’t degrade in the presence of minerals and salts, and will stand up to the elements and water.

    The main downside of an inflatable tub is of course that you’ll need to inflate it before use. This can be a hassle if you’re using a manual hand pump. So we include an electric air pump (worth $149) for free with every Supertub, so you can inflate it to the correct pressure of 10 PSI at the push of a button, and in just 4-5 minutes.

    air pump

    A final point to note is tub size. If you intend to make cold plunging a habit, we recommend a full-sized tub you can use comfortably. A high-sided compact barrel-style tub may feel cramped and will be harder to climb into and out of safely and comfortably, especially when you’re wet.

    3. Filtration and sanitation

    3.1 Three layers of filtration and sanitation

    Most cold plunges come with one or more of the following filtration sanitation devices: a water strainer, a water filter, and an ozone generator. The Supertub uses all three to make sure you’ll have sparkling clean water all day, every day.

    The water strainer is a metal mesh strainer that keeps the water clear of physical debris like hair, sediment, and dirt.

    Supertub cold plunge

    The water filter removes smaller particles like dust, body oils and sweat. Most high-quality cold plunges, including the Supertub, use filters with a filtration grade of 20 microns, for the best balance of cleanliness and filter lifespan.

    Supertub cold plunge

    Finally, the ozone generator handles pathogens and other contaminants on microscopic level, destroying and preventing the proliferation of microbes including viruses, bacteria like E. coli and staph, fungi like Candida albicans (which causes yeast infections), and parasites like Cryptosporidium parvum (a protozoan parasite which infects the intestinal tract and is a leading cause of diarrhea worldwide).

    Supertub cold plunge

    There are two key things to note when you’re looking at the sanitation system of a cold plunge.

    First, some brands (including some which are bigger or more premium-priced) try to save on component costs by replacing the ozone generator with a UV sanitization system instead. We strongly suggest avoiding models that use UV, as ozone provides significantly superior sanitation, water clarity and texture, and odor management in comparison.

    In particular,

    • Ozone destroys biofilm (the slimy film caused by bacteria and microbe buildup), while UV does not;
    • Ozone destroys humic and fulvic acids (byproducts of plant and animal matter decay), while UV does not;
    • Ozone destroys microbes including Cryptosporidium parvum, while UV only deactivates them;
    • Ozone is a micro-flocculent, meaning it eliminates water cloudiness, but UV is not;
    • If your water does get a little cloudy over time, ozone will continue to function, but UV’s efficacy will be impacted (as the cloudiness will absorb the UV light);
    • Ozone from the generator will diffuse throughout the water in the cold plunge system, while UV only affects the water that is passing through the UV chamber;
    • Ozone generator cells do not require replacement, but UV vapor lamps may need to be replaced as soon as every 3-12 months, and disposal must be done carefully as lamp gases are considered hazardous waste.

    Second, check if the water strainer is internally or externally positioned. Internal strainers are positioned behind a panel within the chiller, are often difficult to reach, and require tools such as a screwdriver to access. External strainers are easy to access with no tools required.

    We recommend an external strainer setup to reduce hassle whenever you find yourself needing to rinse out the strainer (which may be once every week or two).

    4. After-sales support

    4.1 Setup

    Modern cold plunges don’t take too long to set up – it can take as little as 15-20 minutes to set up the Supertub. But if you’re brand new to using and maintaining a plunge, it’s easy to make small mistakes that can cause problems (noises, leaks, unexpected errors, etc) which you may find difficult to diagnose and fix without experience. (Our Customer Support team has a list of over 30 potential setup errors that could occur.)

    To avoid these issues, we offer white-glove setup service to customers based in Singapore. A member of our team will go down to your home at a time of your choosing and help you out with the entire process from start to finish.

    For those that prefer DIY, we also provide a comprehensive step-by-step video walkthrough – and you can still reach out to our team via WhatsApp or email if you find that you need help at any point.

    4.2 Maintenance and warranty

    Like a swimming pool, hot tub, or air conditioning system, cold plunges require some maintenance, and you may find yourself needing tune-ups and fixes as the months and years go by.

    Replacements or repairs may be required for any of the over 100 different components or parts that make up a cold plunge, and may take anywhere from a few minutes to a few hours to complete. Some repairs, such as those involving the water pump, may even require soldering equipment.

    These fixes are routine and straightforward to a trained technician, but can be a real hassle for the average consumer.

    Angela Lee Pucci (ONE Women's Atomweight Champion) and Bruno Pucci (x IBJJF NoGi World Champion) enjoying their Supertub

    That’s why we suggest buying from a brand that provides robust local customer support, rather than from international sellers or marketplace dealers who may become unresponsive after closing the sale, may lack sufficient training or interest to help you diagnose and repair any issues, and may not have the the support staff or spare parts needed to help you keep your plunge working smoothly in the long run.

    Supertub customers in Singapore are supported by our dedicated local team who will be available to provide in-home servicing and repairs any time your Supertub may require it. We also provide two years of free warranty coverage – twice what our local and international competitors typically offer – and are committed to providing service and support (including spare parts at cost and maintenance and repair advice) even after your warranty period is over.

    5. Hidden costs

    One final thing to look out for when selecting a cold plunge is hidden fees and costs – such as shipping fees or taxes that are not disclosed up front but added on at checkout, or the cost of returns.

    To our knowledge, we are the only local brand at the time of writing to provide a truly free 30-day “love it or return it” offer – instead of charging a restocking or return fee, or passing return shipping fees and responsibilities on to the customer.

    We also prefer to avoid plying you with expensive upsells and add-ons – like a tub cover for over $300, an electric air pump for $150, or an anti-slip mat for $100. Instead, the Supertub comes with everything you need to start plunging right away, as well as a selection of useful accessories, including:

    • An electric air pump for fast and easy setup;
    • A water filter;
    • An anti-slip mat to help you get in and out of the tub safely, absorb excess water, and keep the area around your tub clean and dry;
    • A skimmer net for fishing out debris (like fallen leaves); and
    • A phone mount so you can document and share your cold plunge progress on your smartphone.

    All in, that comes to about $500 in value thrown in for free.


    We designed the Supertub to be the best cold plunge offer on the market today.

    We gave it excellent specs, a sleek and simple design, and all the features and accessories you’ll need for the complete cold plunge experience– all at an ultra-competitive price.

    Supertub cold plunge

    Some of the key highlights::

    • The product:
      • Powerful 0.8hp chiller that can stand up to an all-day plunge party in hot weather
      • Military-grade inflatable tub that’s easy to maintain and manoeuvre
      • 3-step sanitation system with commercial-grade ozone generator to keep your water super-clean
    • The offer:
      • Just S$4,999 with no added shipping, taxes, or other fees
      • Comes with everything you need, including useful accessories worth $500
      • No lead time – get it in 3-5 working days vs. the industry standard of 4-8 weeks
      • Free white-glove setup and servicing for convenience and peace of mind
      • Free 2-year warranty – double what our competitors are offering
      • Try it risk-free – with truly free 30-day returns

    Limited-time offer

    If you’re ready to take the plunge with the Supertub today, we have one final offer for you.

    Many of our customers have found that the traditional Scandinavian practice of combining sauna and cold plunging works wonders for supercharging their recovery routines.

    So for a limited time, we’re including our best-selling HeatPod Infrared Sauna Blanket (worth S$799) for FREE with every Supertub purchase. Use promo code HOTANDCOLD at checkout to redeem this special offer.

    Get the Supertub today

    • $4,999
    Order now