Chlorine for pools, bromine for hot tubs.

Yes, they’re different, and the right choice depends mostly on temperature.

Chlorine is the standard for pools because it’s cheap, fast-acting, and works fine in cool to warm water. But in hot water (like a spa or hot tub), chlorine breaks down too quickly and creates that strong chemical smell. That’s where bromine comes in.

Bromine is more stable at high temperatures, so it lasts longer in a hot tub and produces less odor. The trade-off is cost — bromine is more expensive and a bit harder to find. It also doesn’t work as well in cold water, so don’t bother with it in a pool unless you’ve got a heated indoor one.

If you’ve got a hot tub, switch to bromine. If you’ve got a pool, stick with chlorine.