Silk Balance - 38oz Once-per-week solution without complicated hot tub chemicals. Safer and easier on the environment and your skin than the harsh chemicals currently used in other spa chemicals. 38 oz bottle lasts for 2 months. Works with Bromine or Chlorine. SilkBalance gives sparkling clear, soft, and pH-balanced hot tub water, you will get all the amazing health and wellness benefits of spending leisure time in your hot tub.