How to Plumb a DIY Cold Plunge: Chiller, Pump & Filter Setup

Building your own cold plunge can save a lot of money, but getting the plumbing right is one of the most important parts of the build. Your pump, filter, chiller, hose size, fittings, and water flow all need to work together.

I've built and tested several DIY cold plunge systems using inflatable tubs, stock tanks, external chillers, pumps, and filtration systems. The basic idea is pretty simple once you understand how the components fit together.

Basic DIY Cold Plunge Water Flow

A typical external cold plunge system circulates water in this order:

COLD PLUNGE → PUMP → FILTER → CHILLER → COLD PLUNGE

Water leaves the plunge through the outlet or suction connection, moves through the pump and filtration system, passes through the chiller, and then returns to the plunge through the inlet.

The exact fittings you'll need depend on your equipment and the inlet and outlet connections on your tub. Stock tanks, inflatable cold plunges, chillers, pumps, and aftermarket bulkhead fittings can all use different connection sizes and thread types.

PVC / Spa Hose vs. Braided Vinyl Hose

I've used two primary approaches for my DIY cold plunge plumbing:

PVC with flexible spa hose: A clean, durable setup that works well for a more permanent cold plunge installation.

Reinforced braided vinyl hose: A simpler, flexible approach that's easy to assemble, reposition, modify, and service.

Both can work very well. The better choice depends on your plunge, equipment, available space, and how permanent you want the installation to be.

Connecting the Plumbing to Your Cold Plunge

Don't assume the fittings at the end of a plumbing layout will connect directly to your particular tub.

The tub connection points shown in my plumbing plans use 1/2-inch fittings. Your cold plunge may use a different size or connection type, so you'll need to determine the size and thread type of your tub's inlet (return) and outlet (suction) before ordering your final connection fittings.

If you're converting a stock tank, stock trough, or another container without existing plumbing connections, you can add bulkhead-style inlet and outlet fittings and then use the appropriate adapters to transition between the bulkheads and the plumbing system.

Get My Complete DIY Cold Plunge Plumbing Plans

If you'd rather skip the trial and error, I've put together the plumbing layouts I use for my own builds.

The downloadable package includes both plumbing approaches:

• PVC + flexible spa hose plumbing plan
• Reinforced braided vinyl hose plumbing plan
• Detailed plumbing diagrams
• Fittings and components lists
• Pump, filter, and chiller placement
• Recommended parts and suppliers
• Tub and stock-tank connection guidance

These aren't theoretical diagrams. They're based on cold plunge systems I've actually built, tested, modified, and used.

GET THE DIY COLD PLUNGE PLUMBING PLANS →

See My DIY Cold Plunge Builds

I also document my cold plunge builds, equipment testing, modifications, and troubleshooting on the Team FITBODY YouTube channel. The videos below show these systems in the real world and can help you better understand how the components fit together.

WATCH MORE COLD PLUNGE BUILDS ON YOUTUBE →

Affiliate Disclosure: Some links to products, parts, or resources on this page and in my plumbing plans may be affiliate links. If you purchase through one of these links, FITBODY.com® may earn a commission at no additional cost to you. That support helps me continue building, testing, and documenting DIY cold plunge systems.

Safety Note: DIY cold plunge systems combine water, plumbing, and electrical equipment. Follow all manufacturer instructions and applicable electrical and plumbing requirements. Use properly protected GFCI electrical circuits and consult a qualified professional when necessary.