Chlorine Vs. Bromine for Pool Sanitization

Chlorine and Bromine are both chemical elements. In their elemental state, as Halogens, they can be dangerous. Bromine is too reactive to exist as a free element in nature and is often found in two different compounds: sodium bromide (naBr) and potassium bromide (KBr), found in seawater.

When we refer to Chlorine and Bromine in the pool industry, we are referring to chemical compounds. Both the chlorine compounds used to sanitize swimming pools and spas AND the bromine compounds used to sanitize swimming pools and spas contain chlorine. Yes, bromine used in pools and spas is chlorine based.

Chlorine has made its name known in the pool industry as king of all sanitizers due to it’s ability to fight algae and bacteria – it does this by oxidizing contaminants – the waste product is chloramines.

Chloramines are what you typically associate with the “chlorine smell” of hot tubs and pools especially at hotels. This is the smell of used up chlorine – a properly balanced pool should not have a noticeable chlorine smell. To stabilize chlorine, conditioner or cyanuric acid is used.

Stabilizer helps to prevent the chlorine from being used up too quickly by the sun or contaminants. Shocking the pool, or super dosing with chlorine helps to reset the chlorine level in a pool – eliminating chloramines and making the chlorine available to sanitizie more algae/bacteria and contaminants. Chlorine’s oxiding power also eliminates organic matter like body oils. Bromine has a lower pH and is less efficient at removing organic debris in water.

Bromine ionizes contaminants – and changing the chemical bonds. Even after combining with contaminants, some bromine remains active, continuing to work. It also produces waste products – called bromamines. These can be reset by shocking.

Bromine is often used in spas because it is stable at higher temperatures (above 75 degrees Farenheit).

Bromine can’t be stabilized the way chlorine can be with cyanuric acid. In an outdoor pool bromine can be easily degraded from the sun – bromine is degraded much more quickly by the sun than chlorine.

Chlorine is convenient because it can easily added to the pool with chlorine tablets. The tablets can be placed in a feeder and released in a controlled rate. Bromine can be dispensed in tablet form as well but it dissolves very slowly. Special equipment is needed to apply bromine in pools.

Chlorine can be either a slow-dissolving or a quick-dissolving sanitizer whereas bromine is typically always a slow-dissolving substance.

The largest obstacle people find to using bromine in your pool as a sanitizer is experience. It requires knowledge and consistency. It is definitely just as effective as chlorine when it comes to killing bacteria but pool professionals debate which one is better. Many people are drawn to bromine because it is not as harsh of a chemical as chlorine.

Not sure which path to take? Discuss your options with your pool builder or local pool service company.

*based on an article first brought to you by AQUA Magazine.