An independent review tested the top 8 shower filter brands under real world conditions. Tests include before and after total residual chlorine (a combination of free chlorine and chloramine) levels using a digital chlorine meter to measure the results. The shower filters are tested for their ability to remove both free and combined chlorine in an actual residential shower unit. This review puts to the test various manufacturer's claims, as to the effectiveness of their chlorine shower filters. the Phresh ™ shower filter ranks the Number One best shower filter on the market.