Chlorine vs bromine: Chlorine for pools, bromine for hot tubs

The key difference is temperature tolerance — chlorine works fine in cool to warm water but breaks down too quickly in hot water, creating that strong chemical smell. Bromine stays stable at high temperatures, lasts longer in hot tubs, and produces less odor, but it’s more expensive and less effective in cold water. Stick with chlorine for pools and switch to bromine for hot tubs.