Sanitiser is the single product keeping your hot tub safe to use. Spa Trade Group's ClearSpa range covers the four sanitiser families used by UK spa owners and small commercial sites: stabilised chlorine, bromine, BCDMH and chlorine dioxide.
How the three main hot tub sanitiser families compare for everyday use, hot water performance and running cost.
| What matters | Chlorine | Bromine | Chlorine dioxide |
|---|---|---|---|
| Best for | Fast, low-cost everyday sanitising | Hot tubs and spas that want a steadier, milder feel | Deep cleans, biofilm removal and problem water |
| Ideal level | 3 to 5 ppm free chlorine | 4 to 6 ppm total bromine | Used as a clean-up dose, not a daily residual |
| Performance in hot water | Burns off faster at spa temperatures | Stays effective in hot water | Used as a strong clean-up dose, often chosen for biofilm problems |
| pH sensitivity | Works best at pH 7.2 to 7.6 | Effective across a wider pH range | Largely unaffected by pH |
| Odour | Noticeable when chloramines build up | Milder than chlorine | Low odour at normal clean-up doses |
| Typical running cost | Lowest day to day | Slightly dearer than chlorine | More per dose, but only used occasionally |
| ClearSpa products | Stabilised chlorine granules and mini tablets | Bromine tablets 20g and bromine granules | Chlorine dioxide |