Cold plunge in a bathtub: how to do it
A cold plunge in a bathtub costs only the ice: about 21 lb for 40 gallons of 60°F tap water. The steps, the ice table and the mould warning owners give.
DIY builds
DIY cold plunge builds, one at a time: the bathtub you already own, a cooler, a stock tank and a home-made chiller. Costs and steps from owner reports.
A DIY cold plunge is one you put together yourself, from the bathtub you already own up to a plumbed stock tank with a chiller. This section takes the builds one at a time. The full parts list, the costs and the five routes side by side are in the DIY cold plunge tub.
We have not built any of these. Each page is assembled from what owners report on the r/coldplunge forum, from makers’ specs and from our own arithmetic, and it says which is which. How we review explains the method.
Where to start
| If you want to | Read | The short answer |
|---|---|---|
| Compare every way to build one | The DIY cold plunge tub | $1,000 to $1,300 for a stock tank with a chiller |
| Try it tonight for the price of the ice | Cold plunge in a bathtub | About 21 lb of ice for 40 gallons, then drain it |
| Build one from a big cooler | Grizzly cold plunge | $1,800 to $2,400 with a chiller, by owners’ counts |
| Start with a farm tank and ice | Stock tank cold plunge | About $150 for a 100 gallon tank. Insulate it and make a lid |
| Add cooling without a $3,000 chiller | DIY cold plunge chiller | $550 to $1,000 for a bare chiller, a pump and a filter in a vented box |
| Know how much ice to buy | How much ice an ice bath needs | Half a pound per 10 gallons, per degree |
| Buy a chiller ready to plug in | The best cold plunge chillers | A 1/3 HP unit for most tubs under 80 gallons |
All DIY builds
Grizzly cold plunge: the cooler build
A Grizzly cold plunge is a 350 or 450 quart cooler with a chiller plumbed in. Owners spend $1,800 to $2,400. Sizes, parts, steps and what went wrong.
Stock tank cold plunge: tank, lid and ice
A stock tank cold plunge starts with a 100 gallon farm tank at about $150. Which tank to buy, how to insulate it, the cover to make and when to add a chiller.
DIY cold plunge chiller for under $1,000
A DIY cold plunge chiller is a bare aquarium chiller, a pump and a filter in a vented box. Owners build one for $550 to $1,000. Parts, order and mistakes.