How does the UV sterilizer system work? May 14, 2018 03:55 Updated Follow The ultra-violet light sterilizing system can kill up to 99.9% of viruses and bacteria in spa water. Using a UV Sterilizer system in addition to spa chemicals will provide the safest possible spa pool water. Related articles What does the blue light on the side panel of my spa mean? Can I shut down my spa while I am on holiday? What is an Ozone Water Clarifier? What is BioGuard Perfect Balance used for? How do I operate and maintain my spa? Comments 0 comments Article is closed for comments.