Crystal Quest bath ball replacement filter removes chlorine, chloramines, VOC’s, THM’s, pesticides, sulfur, heavy metals, hydrogen sulfide (“rotten egg” odor), iron oxides (“rust water”), dirt, sediment and other odors. Water travels through both ERA-6500 and ERA-9500 media for de-chlorination and enhances pH balance. Periodic reversing of disk ensures balanced filtration, eliminates the potential for channeling, and extends the useful life of the disk. Capcity 18 to 24 months