The Crystal Water Monitor works well with Pools, Spas and SwimSpas that use an Ozone Generator. Although Ozone system will destroy contaminants in your water, you will still need chlorine at a reasonable level to maintain sanitizer effectiveness.
Ozone systems still require chlorine for a few key reasons, primarily because ozone doesn’t provide the necessary residual sanitation and can break down other chemicals. Ozone sanitizes water as it passes through the system, but it is a very reactive molecule that doesn’t remain in the water long enough to kill bacteria and contaminants introduced by users. A small amount of chlorine or bromine is still needed to provide a constant, “in-the-water” level of sanitization, ensuring the pool or spa is protected between ozone treatments. This extra chlorine also helps to maintain a sufficient ORP level.