One of the most common questions we get asked from spa and hot tub owners is which is the best sanitiser to use – Chlorine or Bromine? There are many theories out there as to which is better, however we decided to gain firsthand experience and run our test hot tub on both in order to provide you with a practical answer. The conclusion we came to is that both are perfectly suitable sanitisers, however bromine does boast three crucial advantages over chlorine, which we believe makes it a more suitable sanitiser for hot tubs.
Less odorous – Running your spa on chlorine can create a strong chlorine smell in the water even when the chlorine level is kept within the recommended range of 2-4 ppm. Although this is perfectly normal it can result in an unpleasant bathing experience. Bromine is less odorous than chlorine and as a result this smell doesn’t exist and a more pleasant bathing environment can be enjoyed.
Effective at a broader pH range – The recommended pH level for a chlorine spa is 7.2 – 7.6. This is because the effectiveness of the chlorine as a sanitiser significantly decreases at higher pH levels. Bromine on the other hand, is an active santiser at pH levels of 8.2, therefore the pH level can be maintained at a much broader range of 7.2-8.2. This allows more flexibility when controlling the pH level and is particularly beneficial for hard water areas where the incoming water supply naturally contains high pH and alkalinity levels.
Slower dissolving – Regardless of which sanitiser you use, both are available in tablet form and ideally should be used in conjunction with a floating dispenser. The main difference we experienced is that bromine is much slower dissolving than chlorine and as a result it is a lot easier to maintain the correct sanitiser level in the water. This is crucial in order to reduce the amount of work involved in maintaining your hot tub.
To make this a fair argument it is only right that we look into the disadvantages of using bromine over chlorine. As bromine is slow dissolving it can have difficulty in recovering an adequate concentration after the hot tub has been heavily used or is started up after being emptied. In this case you need to add another sanitiser such as oxy shock or stabilised chlorine granules just to boost the level. Another disadvantage is price, as bromine is a little more expensive than chlorine.
Despite these drawbacks we firmly believe that the advantages of using bromine over chlorine far outweigh the disadvantages. As a result we would always recommend using bromine as opposed to chlorine in a hot tub.