The ProClear Spa Sanitizer delivers a more efficiently sanitized, easily maintained, and odor-free hot tub. ProClear 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 Biaguanides. Use in conjunction with the CLEARRAY Water Purification System for clean, clear water. Available in the U.S. and Europe, not available in Canada.