The highly reactive O 3 gas oxidizes organic waste products in the pond. The waste products are basically decomposed. The ozone gas is used up in the process and is non reactive. The ozone breaks down into an oxygen molecule again. Ozone can be used in ponds to help control algae and water clarity.
Ozone oxidizes the algae spores.
Additionally, some of the algaes nutrients are decomposed which helps inhibit algae growth. Evidence suggests that ozone can help reduce filamentous stringy algae on the pond walls. Ozone burns these DOC s and imparts a crystal clear and healthy look to the pond. These effects are a bonus over standard pond ultra-violet sterilizers. An overdose of ozone can burn your fish s gills.