The best stock tank cold plunges
The stock tank is the original DIY plunge: a livestock trough, a cover and a chiller. It is still the cheapest route to a large, durable tub — as long as you buy a tank deep enough to sit in.
Before purpose-built plunges existed, people bought livestock troughs. Plenty still do, and for good reasons: a galvanized stock tank is stronger than any inflatable, costs a fraction of a branded tub, comes in sizes no plunge maker offers, and looks better in a garden than a plastic pod. The catch is that a stock tank is designed to water cattle, not to immerse a person, and three of its design decisions work against you.
Quick picks
| # | Product | Best for | Key spec | Price |
|---|---|---|---|---|
| 1 | Behlen Country 78-Gallon Galvanized Round Stock TankThe smallest galvanized tank still listed at plunge size. Galvanized steel conducts, so it cools fast with ice and warms fast in sun — which is the whole trade of this format. | The smallest usable galvanized tank | 78 gal, galvanized steel, round | |
| 2 | Behlen Country Galvanized Stock Tank, 100 Gallon, 2 × 2 × 4 ftThe 2 × 2 × 4 foot tank that most DIY plunge builds are based on, from an established farm brand — sold, on the listing we checked, in threes. | The classic plunge dimension | 100 gal, 24 × 24 × 48 in, 132 lb — listed as a pack of three | |
| 3 | Rubbermaid Commercial Structural Foam Stock Tank, 300 GallonPlastic rather than steel, which means it does not corrode and is warmer to the touch — and at 300 gallons it is a two-person tub rather than a one-person one. | Two people, or full-length immersion | 300 gal, structural foam, US-made commercial tank | $369.98 · View on Amazon $483.99 · 24% off |
| 4 | Rubbermaid Commercial Structural Foam Stock Tank, 50 GallonA well-made tank and a poor plunge, included here so you can see the trap: 50 gallons spread 12 inches deep is a trough, not something you sit in. | Legs and forearms only | 50 gal but only 12 in deep — 52 × 31 × 12 in | |
| 5 | Plunge Crafters Insulated Stock Tank Cover, 100 GallonMarine-grade vinyl and a size cut for one specific tank, which together are what separate a cover that seals from a tarp with a drawstring. | The overall cover pick | Cut for 100-gallon stock tanks, marine-grade vinyl, 13 lb | |
| 6 | AS ColdPlunge 1/3 HP Chiller, Built-In Filter and PumpThe integrated pump and filter is the reason to pick this one: an external-pump chiller needs three more purchases and four more hose connections to reach the same place. | The overall chiller pick | 1/3 HP, cools to 42 °F, pump and filter built in |
#ad Amazon links are affiliate links. Tap any row to jump to that product's full write-up. Prices are Amazon's own, as of Sep 27, 2026; confirm the current price on Amazon.
The three things a stock tank was not designed for
- 1Depth. Cattle drink from the top. A 50-gallon tank here is 12 inches deep — a wash, not a plunge. You want at least 24 inches, and 24 is the shallow end of usable.
- 2Insulation. Bare steel is a radiator. A galvanized tank exchanges heat with the air constantly, which means a chiller runs harder and ice melts faster. An insulated cover is not optional here, it is the single highest-value item on this page.
- 3Temperature. Steel gets uncomfortable to touch in hard frost and hot to touch in direct summer sun. Siting matters more than it does with a plastic tub.
The picks side by side
| Capacity | Dimensions | Material | Deep enough? | |
|---|---|---|---|---|
| Behlen 78 gal round | 78 gal | Not published | Galvanized steel | Not published |
| Behlen Country | 100 gal each | 24 × 24 × 48 in | Galvanized, rust-resistant | Yes — but listed as a pack of three |
| Rubbermaid 300 gal | 300 gal | Not published in the listing | Structural foam | Yes; more water than most need |
| Rubbermaid 50 gal | 50 gal | 52 L × 31 W × 12 H in | Structural foam | No — 12 in deep |
From each Amazon listing, read on 2026-09-12; buy boxes checked the same day.
Galvanized or plastic?
Galvanized steel is stronger, looks better and lasts longer outdoors. Structural foam — what the Rubbermaid tanks are made of — is lighter, warmer to the touch, insulates marginally better, and will not corrode where the coating is scratched. For a plunge that lives outside in a cold climate, we would take galvanized and an insulated cover. For a plunge on a deck or in a garage where knocks are likely, plastic is the sensible choice. Neither is insulated in any meaningful sense; that is what the cover is for.
The build, in order
- 1The tank. At least 24 inches deep, sized so the water covers your shoulders when you sit. Our DIY cold plunge guide covers the layout.
- 2A level base. A filled 100-gallon tank is more than 800 pounds of water. Level ground, paving or a deck rated for it — not grass that will subside on one side.
- 3An insulated cover. Cut for the tank shape. It keeps leaves out, keeps cold in, and cuts what the chiller has to do.
- 4A chiller with filtration, if you are not using ice. Match the capacity to the volume — our chiller sizing guide does the arithmetic, and a 300-gallon tank is a lot of water to hold at temperature.
- 5Water care. Stock tanks are open, outdoors and usually uncovered while in use, so they collect more debris than an indoor tub. Filtration and water treatment matter more here, not less.
The picks in full
Behlen Country 78-Gallon Galvanized Round Stock Tank
Behlen Country
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
The smallest galvanized tank still listed at plunge size. Galvanized steel conducts, so it cools fast with ice and warms fast in sun — which is the whole trade of this format.
| Capacity | 78 gallons |
|---|---|
| Material | Galvanized steel |
| Shape | Round |
| Model | 50130118C |
| Dimensions | Not published in the listing |
| Availability | Usually ships in 2 to 3 weeks, per the listing |
What works
- Galvanized steel outlasts any inflatable
- 78 gallons is a one-person volume a small chiller can hold
- Farm-supply construction rather than a wellness product
What doesn't
- The listing publishes no dimensions or depth
- Steel conducts heat, so an uninsulated tank warms quickly outdoors
- Ships in two to three weeks rather than immediately
Skip it ifyou need a known depth before you buy. The 100-gallon Behlen publishes 24 × 24 × 48 inches; this one publishes nothing.
Behlen Country Galvanized Stock Tank, 100 Gallon, 2 × 2 × 4 ft
Behlen Country
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
The 2 × 2 × 4 foot tank that most DIY plunge builds are based on, from an established farm brand — sold, on the listing we checked, in threes.
| Capacity | 100 gallons each |
|---|---|
| Dimensions | 24 L × 24 W × 48 H in |
| Weight, as listed | 132 lb — the listing does not say whether that is per tank or for the pack |
| Material | Galvanized steel, rust-resistant |
| Quantity on the listing we checked | 3 — the title says Quantity 3 and the data says Number of Items: 3 |
| Part number | 50130028-09 |
| Color | Silver |
What works
- The 2 × 2 × 4 ft dimension the DIY plunge community has settled on
- An established farm brand rather than an anonymous listing
- 100 gallons holds temperature better than a 70-gallon tank
What doesn't
- Listed as a pack of three — excellent value for a gym, a surprise for a household
- The 132 lb weight field does not say whether it is per tank or for all three
- Bare galvanized steel, so an insulated cover matters even more
Skip it ifyou want one tank. Check the quantity field on the listing before you order.
Rubbermaid Commercial Structural Foam Stock Tank, 300 Gallon
Rubbermaid Commercial Products
$483.99 · 24% off
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
Plastic rather than steel, which means it does not corrode and is warmer to the touch — and at 300 gallons it is a two-person tub rather than a one-person one.
| Capacity | 300 gallons |
|---|---|
| Material | Structural foam (RigidCell construction) |
| Dimensions | Not published in the listing data we read |
| Origin | Made in the USA |
| Range | Rubbermaid BRUTE farm products — weather, impact and corrosion resistant |
| Model | Commercial stock tank, 300 gal |
What works
- Will not corrode where the surface is scratched
- Warmer to the touch than steel in a hard frost
- Large enough for full-length immersion or two people
What doesn't
- 300 gallons is a great deal of water for any chiller to hold at temperature
- The listing data does not publish dimensions
- Plastic looks like a farm tank; steel at least looks deliberate
Skip it ifyou plan to run a domestic chiller. Sizing a chiller to 300 gallons is a different, larger problem.
Rubbermaid Commercial Structural Foam Stock Tank, 50 Gallon
Rubbermaid Commercial Products
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
A well-made tank and a poor plunge, included here so you can see the trap: 50 gallons spread 12 inches deep is a trough, not something you sit in.
| Capacity | 50 gallons |
|---|---|
| Dimensions | 52 L × 31 W × 12 H in |
| Material | Structural foam, ribbed base, built-in body stiffeners |
| Warranty, per the listing | 10-year limited |
| Origin | Made in the USA |
| Design note, per the listing | Shallow 12 in height, for smaller animals to drink from |
| Model | FG424300BLA |
What works
- A 10-year limited warranty, which nothing else here carries
- US-made commercial construction
- Genuinely useful for a legs-and-forearms cold soak
What doesn't
- 12 inches deep — you cannot get your shoulders under the water
- Its own listing describes the shallow height as a feature for small animals
- Wide and shallow is the worst shape for holding cold
Skip it ifyou want full immersion. Read the height dimension on any stock tank before the gallons.
Plunge Crafters Insulated Stock Tank Cover, 100 Gallon
Plunge Crafters
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
Marine-grade vinyl and a size cut for one specific tank, which together are what separate a cover that seals from a tarp with a drawstring.
| Fits | Rubbermaid 100-gallon stock tanks |
|---|---|
| Material | Marine-grade vinyl |
| Insulation | Built in |
| Weight | 13 pounds |
| Water resistance | Waterproof |
| R-value | Not published |
What works
- Cut for a named tank rather than sold as a generic round cover
- Marine vinyl is the correct material for permanent outdoor exposure
- Heavy enough at 13 lb to stay put in wind, which lighter covers do not
What doesn't
- No R-value or published heat-loss figure — "insulated" is a description, not a number
- Only fits the tank it was cut for; measure before ordering
- 13 lb is a real lift on and off before every session
Skip it ifyour tub is not a 100-gallon stock tank. A cover that does not fit seals nothing, and this one is cut to a specific shape.
AS ColdPlunge 1/3 HP Chiller, Built-In Filter and Pump
AS ColdPlunge
#ad Price as of Sep 27, 2026. We earn a commission if you buy, at no extra cost to you. How this is funded.
The integrated pump and filter is the reason to pick this one: an external-pump chiller needs three more purchases and four more hose connections to reach the same place.
| Cooling capacity | 1/3 HP |
|---|---|
| Minimum temperature | 42 °F |
| Pump | Built in, submersible |
| Filtration | Built in |
| Hoses | Insulated, included |
| Duty cycle | Rated for 24/7 operation |
| Fits | Cold plunge tubs and bathtubs |
| Pull-down time | Not published |
What works
- Pump and filter integrated — one box, one plug, no shopping list
- A 42 °F floor is cold enough for any protocol worth running
- Insulated hoses included rather than sold as an upgrade
What doesn't
- 1/3 HP is slow to pull a large tub down from ambient
- The 42 °F floor is warmer than the 37–39 °F the 1 HP units claim
- No published pull-down time, so sizing is arithmetic you do yourself
Skip it ifyour tub is over roughly 100 gallons or lives outdoors in a hot climate. At 1/3 HP you will be waiting overnight for a pull-down a 1/2 HP does in an afternoon.
What a stock tank actually saves you
Be clear-eyed about this. The tank is the cheap part of a cold plunge; the chiller is not. If you are going to run a chiller, a stock tank saves you the cost of a tub and nothing else — and a purpose-built insulated tub will hold temperature better for the same chiller. Where the stock tank genuinely wins is the ice route: a big, cheap, durable, easily hosed-out tub that you fill and drop bagged ice into, with no compressor, no continuous power and nothing to service. Our chiller vs ice page compares the two properly.
The one we would skip
A 12-inch-deep tank. The 50-gallon Rubbermaid above is included precisely so you can see the shape of the mistake — it is a fine tank and a poor plunge, because you cannot get your shoulders under 12 inches of water. Stock tanks are sold by gallons, and gallons in a wide shallow trough are not gallons you can sit in. Read the height dimension, every time.
Questions people actually ask
Can you use a stock tank as a cold plunge?
What size stock tank is best for a cold plunge?
Do you need to insulate a stock tank cold plunge?
Galvanized or plastic stock tank for a cold plunge?
Sources
- Amazon.com — galvanized stock tank listings, specifications as published by the sellers — checked Sep 12, 2026
- Amazon.com — stock tank cold plunge listings, specifications as published by the sellers — checked Sep 12, 2026
- NIST Chemistry WebBook — properties of water, for the weight figure — checked Sep 12, 2026
Read next
- DIY cold plunge guideThe whole build.Read it
- Best cold plunge coversThe item that matters most.Read it
- Chiller vs iceWhere a stock tank really wins.Read it
- Best outdoor cold plungesPurpose-built alternatives.Read it
- Chiller sizing guideCapacity against volume.Read it
- Best cold plunge stepsGetting into a tall tank.Read it
Every pick on this page comes from published specifications, not from hardware we own. Read how we pick — including what spec-led ranking cannot tell you.