The Natural Shower is the best performing NSF Certified shower filter on the market. Most shower filters reduce less than 90% of Chlorine initially, and quickly drop off to 50 - 60% reduction. That"s leaving half the Chlorine in your water! Even at the end of its cartridge life the Natural Shower continues to reduce more than 89% of Chlorine.The Natural Shower also offers industry leading performance in sediment heavy waters. The patented KDF chamber was designed in collaboration with KDF Labs and allows the Natural Shower to perform in problem water areas where other showers clog up in days or weeks.The Naturally Filtered Shower Filter also utilizes a unique backwashing feature which can dramatically extend the life of your cartridge. Those familiar with the Wellness Filter will recognize this system right away, as the design and filtration are the same. They are built by the same people that made the Wellness Filter. The cartridge is white rather than black in the Wellness Filter, and it"s a bit shorter due to the lack of Wellness Enhancement media. The filtration is exactly the same even though Wellness claimed a two year cartridge change vs the recommended one year for the Naturally Filtered version (the enhancement media was expensive, so they recommended keeping the cartridge longer). Though the cartridge will fit the Wellness Filter, we recommend buying a new matching Naturally Filtered unit.