Ozone and UV sanitisation technologies are powerful tools for improving swimming pool water quality. Ozone, created through electrical discharge or UV light, offers strong oxidation to neutralise contaminants, while UV light disables microorganisms by damaging their DNA. When combined, ozone and UV light generate hydroxyl radicals, which are highly reactive and help break down a broader range of pollutants, including chloramines.

Ozone is a molecule consisting of three oxygen atoms (O₃) and is typically generated using an ozone generator that employs electrical discharge to split oxygen molecules (O₂) into individual oxygen atoms, which then recombine to form ozone. As a potent oxidising agent, ozone breaks down and neutralises contaminants like bacteria, viruses, and organic compounds through oxidation, where ozone molecules attack and disrupt the cell walls of microorganisms, rendering them harmless. Ozone decomposes rapidly into oxygen, leaving no harmful by-products, making it an environmentally friendly disinfectant.

UV sanitisation uses UV-C light to damage the DNA or RNA of microorganisms, preventing them from replicating and rendering them inactive. It provides instant disinfection without chemical by-products but requires continuous water flow to be effective, as it does not offer residual protection like ozone or chlorine.

When ozone and UV systems are combined in pool sanitisation, they complement each other to enhance the disinfection process by creating hydroxyl radicals (•OH), which are highly effective in breaking down organic contaminants. Ozone, when exposed to UV-C light, breaks down into oxygen (O₂) and oxygen atoms (O), which then react with water molecules (H₂O) to produce hydroxyl radicals. These hydroxyl radicals are among the most reactive species known in water chemistry and are highly effective at oxidising a broad range of contaminants, including bacteria, viruses, oils, and organic debris. More reactive than ozone, chlorine, or other sanitisers, hydroxyl radicals rapidly neutralise a wider variety of pollutants and chloramines, making the combination of ozone and UV a powerful disinfectant system.