Replace the imitation RO membrane with a quality unit like Buckeye sells, Dow Filmtech 75gpd. You only need to replace the membrane, not the housing. Ditch the cheesy little horizontal DI canister and think about buying an add on unit from Buckeye. They have an internal cartridge that you pack tight with DI resin and then place it in the housing. A very simple upgrade that will create genuine, long lasting results.