The traditional method of keeping a hot tub free from unwanted microorganisms involves the addition of copious amounts of bromine or chlorine. Yet these substances lead to skin irritation for many people. Fortunately, recent developments in hot tub sanitation have led to some equally effective techniques. Read on to learn about three alternative methods of sanitizing a hot tub. Metal Ions Metals such as silver and copper, when in their ionized states, are highly effective at eliminating common microorganisms such as bacteria and algae.