Chlorine is cheaper, faster acting and easier to test, so it suits most hot tub owners. Bromine is gentler on skin, smells less and stays stable in hot water, so it suits sensitive skin and heavy users.
Quick comparison
| Chlorine | Bromine | |
|---|---|---|
| Target level | 3–5 ppm | 4–6 ppm |
| Cost | Lower | Higher |
| Smell | Noticeable if levels drift | Milder |
| Stability in hot water | Good | Very good |
| Skin feel | Can dry skin | Gentler |
Chlorine tablets or granules?
Granules dissolve quickly and are good for dosing after each use. 20 g chlorine tablets dissolve slowly in a floating dispenser and keep a steady level between uses. Many owners use both: tablets in the floater and a small dose of granules after a busy session. Never use large 200 g swimming pool tablets in a hot tub.
How to switch
Don’t mix chlorine and bromine. If you want to change, drain, clean and refill the hot tub first.
Keep it simple
Test two or three times a week, adjust pH first (7.2–7.6), then sanitiser, and shock weekly. Our hot tub maintenance guide covers the full routine, and you can order everything from our hot tub chemicals range.
For safe storage and handling of chemicals, see guidance from the Health and Safety Authority.
Frequently asked questions
Can I put chlorine tablets straight into a hot tub?
No. Always use a floating dispenser. Loose tablets can bleach and damage the shell or the filter.
Is bromine better for inflatable hot tubs?
Either works. Chlorine is more common in inflatables because it is cheaper and simple to dose.
Why does my hot tub smell of chlorine?
A strong smell usually means chloramines from used chlorine, not too much chlorine. Shock the water and check your pH.
How often should I add chlorine?
Check levels two or three times a week and top up granules after each use, or let tablets in a floater do the work.
Order your hot tub chemicals
Chlorine, bromine, test strips and starter kits, delivered nationwide.
