Our systems measure dissolved ozone in the return from the pool, and just prior to further ozonation. Some questions were raised whether dissolved ozone is toxic to humans. It is absolutely certain that dissolved ozone is by far loss toxic than equivalent levels of chlorine or bromine. One has to realize that over 100,000 people have died as result of exposure to chlorine while nobody ever died in the same period from exposure to ozone. Bromine, ozone and hydrogen peroxide have been used successfully in the past with or without chlorine residual.
Ozone is the strongest and most convenient disinfectant of all.
Its stability in water is most convenient and it appears to be ideal. Present technology allows easy automatic maintenance of the appropriate ozone residual level. Ozone assists flocculation of organic waste materials, thus enhancing the effectiveness of sand filters. Ozone directly decomposes organic waste by oxidation. Unused ozone slowly decomposes to normal oxygen and remains dissolved in the water to the point of saturation.