Comparison
Hot tub vs swim spa: size, power and upkeep
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In short
A swim spa is a long tub, often around 4 to 6 metres, with a current to swim or exercise against and a seating area at one end. A hot tub is far smaller, holds much less water and is built for sitting and relaxing. Swim spas need a large reinforced base and a dedicated electrical supply; an inflatable hot tub usually runs from a 13 A socket.
Products for this job
Compare all 6 productsMSpa Tidal: semi-rigid 6 seater with hydro jets
Check price on AmazonAffiliate linkLay-Z-Spa 60001: 4 seats, 669 L, 120 AirJets
Check price on AmazonAffiliate linkLay-Z-Spa Milan AirJet Plus: 6 seats, 916 L
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Swim spas sit between a hot tub and a small pool. They look like a long hot tub with a powerful current at one end, so you can swim on the spot, walk or do exercises, then sit in the warm end. The extra length brings extra water, weight, power and cost to set up. This comparison sets out what changes when you step up from a hot tub, so you can judge whether your garden and budget suit one.
What a swim spa is
A swim spa is a hard shell tub, usually acrylic, long enough to swim against a current produced by strong jets or a propeller system. Many have a separate seating zone with massage jets, and some have a divider so the two ends can be held at different temperatures.
Because of the size, swim spas are almost always installed as permanent fixtures. They are delivered by lorry, often lifted into place by crane or moved on skates, and need a reinforced concrete base.
Side by side
Figures are typical ranges. Check the exact model's specification before planning anything.
| Point | Inflatable hot tub | Swim spa |
|---|---|---|
| Typical length | About 1.5 to 2.2 m | About 4 to 6 m |
| Water volume | About 600 to 1,200 L | Several thousand litres |
| Main use | Sitting and soaking | Swimming on the spot, exercise and soaking |
| Power supply | Usually a 13 A outdoor socket | A dedicated supply fitted by an electrician |
| Base | Level slab, decking or pavers | Reinforced concrete base designed for the load |
| Set-up | Self install in an afternoon | Delivery, lifting and installation team |
| Movable | Yes | No |
Weight and base
Water weighs about 1 kg per litre, so even a 900 litre inflatable tub weighs close to a tonne when filled with bathers in it. A swim spa holding several thousand litres is many times heavier. That load must sit on a base designed for it, and some sites need a structural engineer's advice.
Our article on how much a hot tub weighs shows how to add up water, tub and bathers for your base.
- Level concrete slab
- Decking: check it is rated for the load
- Compacted, level gravel with a mat
Power, heating and upkeep
Heating thousands of litres takes more energy than heating a small tub, and swim spas usually have bigger pumps and heaters. They need a dedicated supply designed by a qualified electrician. An inflatable tub on a 13 A plug is limited to a heater of roughly 2 kW, which is why it heats more slowly but needs no new circuit if a suitable outdoor socket is already in place.
Water care follows the same principles in both: filtration, a sanitiser and balanced pH. With a swim spa you simply buy more chemicals and filters, and a full drain takes much longer.
Note:Hot tubs combine water and mains electricity. Use a weatherproof outdoor socket protected by an RCD, follow the maker's manual, and have any new circuit or socket fitted by a qualified electrician.
Which suits you?
- You want to relax with family or friends: a hot tub. Our best inflatable hot tubs guide is a good place to start.
- You want to swim or exercise at home and have space for a permanent installation: a swim spa.
- You rent, may move or want to try hot tub life first: an inflatable tub.
- Your garden is small: a 2 to 4 person inflatable fits far more spaces. See our compact tub guide.
Questions to ask before buying either
Measure the access route as well as the spot. A swim spa needs a clear path for delivery or a crane lift, while an inflatable tub arrives in a box. Check where water will go when you drain it, how far the socket or supply is from the tub, and whether neighbours will be overlooked.
If you are unsure about planning rules for a permanent structure, read our note on planning permission for hot tubs and check with your council.
Frequently asked questions
Can you swim in a hot tub? No. Even large hot tubs are too short to swim. A swim spa uses a current so you can swim on the spot.
Is a swim spa just a big hot tub? It shares the same parts, but it is longer, holds far more water and adds a swim current. Most need permanent installation and a dedicated electrical supply.
Can a swim spa be inflatable? Inflatable swim spas are rare. Almost all are hard shell acrylic units installed on a reinforced base.
Which is easier to keep clean? A hot tub, because there is much less water to filter, test and treat, and draining and refilling is quicker.
What you need
- Check price on AmazonAffiliate link
MSpa Tidal: semi-rigid 6 seater, 930 L
- Check price on AmazonAffiliate link
Lay-Z-Spa 60001: 4 seats and 669 L