Bromine, used to treat swimming pools and spas, is generally composed of bromochlorodimethylhydantoin. When it dissolves in water, it releases hypobromous acid (or free active bromine), which eliminates contaminants such as bacteria and algae.

Free bromine refers to the amount of bromine available to disinfect water. It is made up of two chemical species: hypobromous acid (𝐻𝑂𝐵𝑟) and hypobromite ions (𝐵𝑟𝑂^-). Together, they form the total concentration of free bromine, expressed in ppm (mg/L). Only hypobromous acid 𝑯𝑶𝑩𝒓 is effective on sources of contamination, which is why it's called active free bromine.

Not necessarily! Bromine's ability to disinfect depends on its composition. Only hypobromous acid (𝐻𝑂𝐵𝑟), also known as active free bromine, is truly effective against contaminants. Hypobromite ions (𝐵𝑟𝑂^-), on the other hand, have no disinfectant action. That's why it's important to keep a close eye on your pool, using test strips.

Chlorine (which releases hypochlorous acid) is a rapid disinfectant, ideal for shock or continuous treatment. Bromine, on the other hand, remains active at high temperatures and works best in spas or heated pools. What's more, it's less sensitive to pH variations than chlorine.

Is an untreated pool necessarily dangerous? No. Pool water as a disease factor is above all a matter of probabilities. By minimizing the risks with rigorous monitoring, frequent cleaning of the walls and a high-performance filtration system, it's perfectly possible to obtain good-quality water without chemical treatment.

In short: Bromine is a disinfectant that is particularly well-suited to heated pools and spas, as it remains effective even at high temperatures and is more resistant to pH variations than chlorine. What's more, its disinfectant action is less affected by organic residues, making it an ideal choice for specific environments requiring constant, stable disinfection.