Inflatable hot tubs, judged on the bill rather than the bubbles

Why this sits on a pool site

Because it is the same decision, made in the same corner of the same yard, by the same person. An inflatable hot tub is a soft-sided vessel you site on level ground, fill from a hose, treat with chemicals, cover when unused and drain periodically. Everything this site says about ground preparation, water chemistry and running costs applies, and most of the buying advice you will find elsewhere ignores all three in favor of jet counts.

It is also the honest alternative for a yard that cannot take a pool. Our small-yard guide ends with people concluding they have nowhere for a 12-foot circle; a 77-inch round tub is a genuinely different footprint.

The specs that matter, in order

The running cost, and why we are not printing a number

This is where most reviews quietly invent a figure. We will not, because the inputs are not published: manufacturers in this class publish jet counts and dimensions but not heater wattage, and the actual consumption depends on your electricity rate, your ambient temperature, how often the lid comes off and whether the tub is on a cold slab or an insulated base.

What we can tell you is the shape of it. Unlike a seasonal pool, a hot tub is heated all the time, so the electricity is continuous rather than seasonal — it is the dominant cost of ownership by a wide margin, and it dwarfs the purchase over a couple of years. The arithmetic is the same as our pump electricity guide: find the appliance’s kilowatts, multiply by hours and by your own rate. If the wattage is not on the listing, it will be on the unit, and it is worth asking before you buy.

Three levers genuinely move that number, and they are all free or nearly so. Put the cover back on every single time. Put something insulating underneath, because a tub sitting directly on a cold slab loses heat downward all night. And site it out of the prevailing wind, for the same reason a windbreak helps a pool — our season extension guide covers that mechanism.

Siting it: the same rules, tighter

A hot tub holds less water than a pool but concentrates it into a much smaller footprint, so the load per square foot is comparable and the level tolerance is no more forgiving. The ground has to be flat, firm and free of anything sharp, and it has to stay that way — our leveling guide and surface guide both apply directly, and the surface guide’s warning about decks applies with more force here, not less.

The electrical side is the part to settle before you buy. These units plug into a standard outlet, but it must be a properly protected outdoor outlet, and an extension cord is not an acceptable substitute for one — the reasoning in our electrical safety guide is the same, and the consequence of getting it wrong is worse because the appliance runs continuously.

Chemistry: a small volume that never gets drained seasonally

This is the biggest practical difference from a pool and the thing most new spa owners underestimate. A few hundred gallons at body temperature with four adults in it is a far heavier bather load per gallon than any pool on this site — the arithmetic in our swimmer load guide is the same principle with a much smaller denominator.

Heat also works against chlorine, which is precisely why bromine is the conventional choice for spas. Our bromine versus chlorine comparison explains why the answer flips between an open pool and a covered tub: bromine tolerates heat and higher pH better, and the sunlight problem that rules it out outdoors barely applies under a lid.

Practically: test more often than you would a pool, expect to change cartridges frequently, and plan on draining and refilling on a schedule rather than waiting for a reason.

Who should buy one, and who should not

Buy one if the yard is too small or too uneven for a pool, if you want something usable outside July and August, or if the appeal is sitting in warm water rather than swimming in cool water. On all three counts it beats a pool comfortably.

Do not buy one if you want hydrotherapy jets, if the electricity bill is the thing you are trying to keep down, or if nobody in the household will reliably put the cover back on. That last one is not a joke — it is the difference between a reasonable running cost and an unreasonable one, and it is entirely behavioral.

If the real question is which of the two to buy at all, the honest comparison is seasonality: a pool is four months of a lot of use, a hot tub is twelve months of a little. Our cost per swim guide is the framework, and it works just as well with “soak” substituted throughout.

What we are scoring

We have not tested these and do not claim to. The scores are our reading of published manufacturer specifications — capacity, dimensions, cover, insulation and cold-weather features — weighted toward the things that decide the running cost rather than the things that decide the listing photo. Where a manufacturer publishes nothing, as with heater wattage, we say so. Our methodology page sets out how that works across the site.

Choosing between one of these and a pool is a question about cost shape rather than price, and the two are opposites. Our hot tub versus pool comparison sets it out: a pool stops costing anything in October and a hot tub never does.

The chemistry is the part people underestimate, because a spa is not a small pool. Our hot tub chemicals guide covers bromine against chlorine at 102 degrees, what is actually in a starter kit, and why the testing cadence is every few days rather than weekly.