The "should I buy a chiller?" question is really a math problem, not a gear question. Most plungers underestimate how fast bagged ice piles up and overestimate the upfront cost of a real chiller setup. Here's the actual 12-month breakdown across the three common DIY paths.
The contenders
- Stock tank + bagged ice — the cheapest entry point, highest ongoing cost
- Chest freezer conversion — moderate upfront, near-zero ongoing
- Chiller-equipped rig — highest upfront, lowest ongoing for daily use
We're assuming a 100-gallon plunge volume, target temp of 50°F, and 4 plunges per week. Adjust the numbers if your habit is different.
Stock tank + ice
The starter setup. You fill it from a hose, dump in ice before each session, plunge, drain weekly.
Upfront
- 100-gallon galvanized stock tank: $120
- Drain plug + adapter: $15
- Total: $135
Ongoing (per week, summer ambient)
- Each session needs about 40 lbs of ice to drop tap water from 70°F to 50°F: $12
- 4 sessions/week: $48
- Less in winter (call it $25/week average): $30/week annualized
12-month total: $135 + ($30 × 52) = $1,695
And you're driving to a gas station with a cooler twice a week.
Chest freezer conversion
A 7–10 cu ft chest freezer, sealed and waterproofed. Holds water at 40–50°F continuously. We have the full build guide here — this is the one we recommend for almost everyone, and our DIY overview post lays out where it fits in the broader build hierarchy.
Upfront
- Used 7 cu ft chest freezer (Marketplace): $150
- Pond liner: $40
- External thermostat (Inkbird): $35
- Silicone, hose, fittings: $30
- Total: $255
Ongoing
- Power: ~$8/month at average U.S. rates ($96/year)
- Water care (peroxide, occasional drain): $40/year
- Total: $136/year
12-month total: $255 + $136 = $391
Chiller-equipped rig
A 1/4 HP aquarium chiller plumbed to a stock tank or insulated tub. Set the dial, walk away. This is the closest DIY equivalent to a $5,000 commercial plunge — pair it with our water care guide so the upgrade lasts.
Upfront
- Insulated 100-gallon tub: $250
- 1/4 HP chiller (used or budget brand): $700
- Pump + plumbing: $80
- Filter housing + cartridge: $40
- Total: $1,070
Ongoing
- Power: ~$15/month ($180/year)
- Filter cartridges: $30/year
- Water care: $40/year
- Total: $250/year
12-month total: $1,070 + $250 = $1,320
The 3-year picture
Year-over-year is where the math really diverges:
| Setup | Year 1 | Year 2 | Year 3 |
|---|---|---|---|
| Stock tank + ice | $1,695 | $3,255 | $4,815 |
| Chest freezer | $391 | $527 | $663 |
| Chiller rig | $1,320 | $1,570 | $1,820 |
The chest freezer is the cheapest setup for almost any time horizon longer than three months. The chiller rig pays off versus ice around month 9, and pays off versus the freezer never (it's nicer, not cheaper). And once you're committed, our temperature guide helps you pick the dial setting that maximizes benefit per minute.
What you're actually paying for
- Ice tier — flexibility. You can move the tub, ditch the habit, change your mind.
- Chest freezer tier — set-and-forget operation at the lowest possible cost.
- Chiller tier — temperature precision, lower noise, easier filtration, prettier rig.
If your goal is "plunge daily for years," the freezer wins by a mile. If your goal is "plunge daily and have it look like a wellness studio," the chiller is worth it. If you're not sure you'll stick with it, ice for the first 60 days, then upgrade.
The hidden variable: your time
An ice run is 25 minutes — drive to gas station, fill cooler, drive home, dump it in. Twice a week is roughly an hour of life. Over a year that's 50 hours. At any reasonable hourly rate for your time, the freezer pays for itself in time alone before you count the cash.
Recommendation
- First 30 days → Stock tank + ice. Prove the habit.
- Day 30 onward → Chest freezer conversion. The Cold Nuts default for a reason.
- Year 2+ if you have the budget → Add a chiller to a nicer tub if you want the upgrade.
Read next
10 Cold Plunge Mistakes (And How to Stop Making Them)