With the Bath Ball Chlorine Replacement Filter (4" x 1") for the Bath Ball, you can easily continue to experience the benefits of a filtered chlorine-free bath!?áThe Bath Ball Replacement Filter is more beneficial than simply filtering the chlorine out of your bathwater supply. With the Bath Ball Replacement Filter (4" Diameter x 1" Wide), you are less likely to experience damage to your plumbing pipes due to the backup or clogging of sediment and bacteria. The Bath Ball Chlorine Filter should be replaced every 12 months for a full year of fresh filtration and protection. The Bath Ball's Chlorine Filter is pH balanced, which means that it maintains a healthy level of hydrogen in your water supply, while carefully removing the harmful sediment and contaminants.