The Spa Frog sytem comprises two canisters, one containing bromine and the other minerals. The Spa Frog minerals enable the bromine level to be minimised so there is less chance of skin irritation and less smell than using chlorine.
If you have a Spa Frog In-Line System built into your spa you simply open the cap on the side of your tub, pull up the holder and snap in one blue mineral cartridge and one yellow bromine cartridge. The mineral cartridge will last approximately 3 - 4 months and the bromine cartridge 2-4 weeks. Alternative, you can use Spa Frog in a special floating dispenser.
Spa Frog is easy to use, although it can sometimes be a bit fiddly to control the bromine level accurately using the adjuster on the side of the yellow bromine cannister.