The Nature2 Spa Sanitizer delivers a more efficiently sanitized, easily maintained, and odor-free hot tub. Nature2 significantly improves the look and feel of your water by providing a more consistent PH balance. Using trace elements of silver, ProClear kills bacteria more effectively than chlorine alone. Your spa water is not only brilliantly clear and soft, but gives you an alternative to chlorine-intensive treatments. Do not mix with Bromine, bromides or Biaguanides.