An ozone generator produces O₃ gas and injects it into the circulating water, where it oxidises bacteria and organic matter before reverting to ordinary oxygen. Because it leaves no lasting residue, ozone sanitises without the smell or skin irritation of chlorine, but it only treats water passing through the circulation loop.
Why it matters when you are comparing products
Ozone reduces how often you drain and refill, which is the main chore of owning a plunge. It does not remove particles, so it works alongside a filter rather than instead of one.
Where this comes up
- How do you keep cold-plunge water clean? — How ozone, UV and filtration divide the work.
- Cold plunges with chillers — Ozone is usually bundled into the chiller.
Reviewed 2026-08-15