Bromine vs Chlorine: Which Hot Tub Sanitizer Should You Use?
Every hot tub needs a sanitizer — the chemical that kills bacteria and keeps your water safe to soak in. For almost everyone, the choice comes down to chlorine or bromine. Both work. They just work differently, and one will suit your tub and your habits better than the other. Here's the plain-English comparison we give customers in our Kitchener, London and Windsor showrooms every week.
The short answer
Chlorine is the everyday workhorse: fast-acting, easy to measure, and the cheapest way to sanitize. Bromine costs a little more but is gentler on skin and eyes, has less odour, and stays effective in hot water longer — which matters, because your spa runs at 38–40°C.
Side by side
| Chlorine | Bromine | |
|---|---|---|
| Speed | Fast — kills quickly, great after heavy use | Slower but steady |
| Hot-water stability | Burns off faster at spa temperatures | More stable at 38–40°C |
| Odour | Noticeable "pool" smell when it's working hard | Much milder |
| Skin feel | Can dry skin and sting eyes at higher doses | Gentler — the usual pick for sensitive skin |
| Cost | Lowest — granules from $19.99 | Slightly more — tablets from $29.99 |
| Best for | Occasional soakers, budget-first owners | Daily soakers, sensitive skin |
If you choose chlorine
You have two formats. Arctic Pure Boost granules ($19.99) dissolve in minutes — add a capful after each soak and you're done. Spa Tabs chlorine tablets ($19.99) sit in a floating dispenser and release sanitizer slowly over days — the low-effort option if you don't want to think about dosing. Many owners use both: tabs for the baseline, a scoop of granules after a busy hot tub night. Check your levels weekly with AquaChek Yellow strips ($9.99).
If you choose bromine
Same two formats. Bromine tablets ($29.99) in a floater are the classic set-and-forget approach. Peak Boost bromine granules ($25.99) act fast when the water needs help now — after a party, or when a test strip reads low. Test weekly with AquaChek Red strips ($9.99).
Can you switch?
Yes — but not by mixing. Chlorine and bromine must never be combined in the same floater or feeder (the reaction is dangerous). The safe way to switch is at your next water change: drain, rinse the shell and any dispenser, refill, and start the new sanitizer fresh. If you're unsure, bring a water sample into any of our showrooms and we'll walk you through it.
What about salt-water spas?
If your Arctic Spa has an Onzen or Spa Boy salt system, it generates its own sanitizer from sea salt blend — you don't need tablets or granules day-to-day, just occasional top-ups. That's a different (and very convenient) system we're happy to demo in person.
Whatever you pick, balance comes first
Sanitizer only works properly when pH sits between 7.2 and 7.8. Out-of-range pH wastes sanitizer and irritates skin — and it's a $8.99 fix with Adjust Up or Adjust Down. Strips, sanitizer, balancer: that's the whole weekly routine, about two minutes.
Questions about your specific tub? Call us at +1-226-240-0114 or visit us in Kitchener, London or Windsor — water care advice is free, no purchase needed.