Swim spas. Can you really swim in one, and which one fits?

1 Can I swim in one?

Yes, in place. Two things decide whether it feels like swimming.

You swim against the current instead of turning at the walls, so a 30-minute swim is 30 minutes of stroke. Whether it feels like real swimming comes down to the open water between the current and the first seat, and how the current is made.

How tall are you?5′5′ 2″5′ 4″5′ 6″5′ 8″5′ 10″6′6′ 2″6′ 4″6′ 6″

Arms overhead you’re about 7′ long, before a kick.

• 12 to 13 ft41 models

  8′ of open water leaves you 1′ to kick · median of 10 that publish it

• 14 to 15 ft60 models

  9′ 6″ of open water leaves you 2′ 6″ to kick · median of 26 that publish it

• 16 to 21 ft85 models

  11′ 6″ of open water leaves you 4′ 6″ to kick · median of 37 that publish it

Open water is the maker’s own figure for the lane; 73 of 186 publish it, so ask the dealer for it on any other model. Arms overhead, a swimmer is about 1.2 times their height. How much room a swimmer needs

Propeller or jets?

• Propeller or paddlewheel 18 models

  A wheel or propeller behind a grate pushes a wide, even column of water with no air in it. Our buying guide rates it the best way to swim in place.

• Jets with no air mixed in 8 models

  Several large jets side by side: more water to pull against than air-injected jets.

• Other jets 152 models

  Air is mixed in on 35, and the maker doesn’t say on 117. Air feels strong on your palm but gives you less water to pull against, so check the spec sheet for which kind it is.

2 What size

Start with the spot in your yard. Then the length that fits it.

The size on the brochure is the outside of the cabinet. Leave room around it for a technician to reach the equipment; one maker, Master Spas, asks for 3 ft.

• 12 to 13 ft41 modelsMedian open water 8′
• 14 to 15 ft60 modelsMedian open water 9′ 6″
• 16 to 21 ft85 modelsMedian open water 11′ 6″

3 Hot tub side

One temperature or two? A hot tub side shortens the lane.

Swimmers like cool water and a hot tub runs 100 to 104°F, so one body of water is always a compromise. 30 of the 186 swim spas we track have a separate hot tub side held at its own temperature, 24 of them 18 ft or longer.

Open water on swim spas 18 ft and longer, median

Swim only12′ 4″

With a hot tub side9′ 8″

Of the 25 models that publish their open water.

4 Where it goes

On a pad, or in the ground. Either way it needs three things ready.

A concrete pad

Full, a swim spa weighs a median 18,600 lb. Hydropool calls pavers, gravel or an ordinary deck unacceptable under one.

Its own circuit

154 of 173 need a 50 or 60 A circuit, and 35 need two or more. An electrician sizes it for your panel.

A way in

A swim spa can’t be turned on its side like a hot tub, so the way in has to be as wide as the spa itself (a median 92 in). Measure every gate and overhead clearance first; where it won’t fit, a crane lifts it over, at extra cost. To sink it in the ground, check that the maker allows it: 105 of 133 models whose makers address it are approved.

5 What it costs

What it costs. Prices where we have them.

• Bullfrog Spas$37,895 to $47,695Swim Series starting prices (MSRP) · 3 of 3 models
• Endless Pools$26,499 to $74,999Maker's list price (MSRP) · 9 of 9 models
• LPI · Catalina Swim Spas, Dr. Wellness$24,599 to $52,499Maker's list price (MSRP) · 23 of 45 models
• Master Spas$25,499 to $54,499Reported price · 12 of 15 models
• Wellis$25,999 to $50,999Maker's list price (MSRP) · 10 of 10 models

For the other 12 brands, a dealer near you quotes the price.

Keeping one warm costs about $57 a month for a typical swim spa, more in a cold climate and when you swim a lot.