Perhaps the best way to sanitize a spa is to empty it after every use, but this is usually not possible, nor is it environmentally friendly. Bacteria from bathers can develop in the tub, so it will be necessary to use a spa sanitizer to kill potentially harmful bacteria and keep the spa's equipment working properly. Chlorine is perhaps the most commonly used spa sanitizer, and while it is effective at killing bacteria, it can be harsh on the skin and in the eyes. Other options such as bromine are available as well, and bromine is not as caustic on the skin as chlorine.
Chlorine as a spa sanitizer is fairly inexpensive and it is easy to add to the spa quickly and effectively. It will kill most of the bacteria in the tub, and it can even help clear up cloudy water to a certain extent. Anyone who has bathed in a hot tub or pool, however, will recognize chlorine's distinctive smell. The odor of this spa sanitizer can be overwhelming and unpleasant, and chlorine is likely to dry out the skin of bathers, leading to itchiness and even redness. Chlorine can also cause a burning sensation in the eyes, so many bathers try to avoid chlorine whenever possible.
Bromine is a good alternative to chlorine as a spa sanitizer. It is also fairly inexpensive and easy to add to spa water, and unlike chlorine, bromine will remain active in the water for a much longer period of time. While bromine can have an odor, it is usually not as overwhelming as that of chlorine. Perhaps the biggest drawback to bromine is its tendency to lower the pH level of the water. This means the spa owner or person maintaining the unit will need to spend more time monitoring the spa's water and adjusting the pH level to keep it safe and comfortable.
Mineral purifiers are relatively new spa sanitizer options, and they are less caustic on the skin, not to mention exceptionally long lasting. These types of sanitizers usually come in stick form, and they are inserted into the spa's filters. One of the biggest drawbacks to this type of spa sanitizer is the cost: mineral purifiers are likely to be far more expensive than both chlorine and bromine. While they can be effective at killing bacteria, they are more likely than chlorine and bromine to be overcome, meaning the water may not be as reliably clean.
