"We found that the UV254 system lives up to and exceeds its claims. We installed a UV254 Sanitizer last July on a pool that receives a great deal of debris from surrounding buildings and trees and is in a subtropical climate with extreme heat and heavy rainfall. These conditions make it very difficult to keep a pool properly sanitized. We tested the effectiveness of the UV254 system by not adding any chemical sanitizer for the first month while running the UV system for most of the day. By itself the UV254 system kept the pool crystal clear."