These kits are for running your spa on bromine. If you are unsure of whether to run your spa on bromine or chlorine please see our Spa Information Section for help and guidance. As your water supply plays a major role in what chemicals you use in your spa, we now supply starter kits for hard and soft water areas. As a general rule if your kettle is free from scale you live in a soft water area. If you do have scale in your kettle you live in a hard water area.