Whilst you could run a Lay Z Spa with no chemicals, you certainly can’t bathe safely without some form of sanitiser present in the water. The filter system just isn’t strong enough on it’s own  Lay Z Spas need their water to be constantly circulated and chemically treated to prevent germs, bacteria and organic compounds from building up, and chlorine or bromine are the best options for effectively killing bacteria and germs in a hot tub.