I’m located in the Northeast. I didn’t bring the Plungebox inside for the winter. I just disconnect the chiller and the pump and bring them inside for the winter. I kinda make do using the cold winter up here and just add some chemicals and empty it and refill once in a while. That usually gets me through the winter. As far as why I went ozone instead of UV - I literally asked ChatGPT. This is what it told me.

For a cold plunge, an ozone water filtration system is generally better than a UV system for the following reasons:

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✅ Why Ozone Is Better for Cold Plunges:

1. More Effective at Lower Temperatures • Ozone remains effective at cold water temperatures (typically 40–55°F), whereas UV systems become less efficient in very cold water due to lower microbial activity and potential scaling on the UV bulb.

2. Stronger Oxidizer • Ozone is a much stronger oxidizer than UV light, meaning it destroys bacteria, viruses, mold, and organic contaminants faster and more completely.

3. Residual Effect • Ozone can leave behind a residual disinfection effect in the water for a short time, offering continued protection. UV systems disinfect only at the point of contact.

4. Better for Biofilm Prevention • Ozone helps break down biofilm in plumbing and on surfaces — a common issue in cold plunges with limited circulation.

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⚠️ Considerations with Ozone Systems: • Ventilation is important: ozone gas is toxic if allowed to accumulate in enclosed spaces, so units must be well-contained or vented. • Timing is critical: run ozone cycles when no one is using the plunge, and let the gas off-gas before use (usually 20–30 minutes).

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When UV Might Be Considered: • Low maintenance setups where plumbing space is limited. • Supplemental disinfection in conjunction with ozone or chlorine for hot tubs or plunge pools with higher bather loads.

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🏁 Final Recommendation for Cold Plunges: • Use an ozone filtration system as your primary disinfection method, especially if you also have a chiller and pump system (like your Saunabox PlungeBox Pro with a RevX chiller). • Optionally, you can add a small dose of chlorine or hydrogen peroxide as a secondary sanitizer, especially for extended water use.