Chitosan Natural Clarifier ~ 6-Pack

Chitosan Clarifier is nature's solution for crystal clear hot tubs & pools, Derived from recycled sea crustacean shells, we add plant-based enzymes. Our less water formula with 2X more active ingredients is far superior to petrochemical-based treatments. Clears cloudy pools & spas with Chitosan Added natural enzymes devour surface oils and fight foam Removes impurities - improves filtration (6) x 16 oz. - Double Concentrated (use less) Product notes: Use just 1/2 oz. weekly. Equivalent coverage as 32oz. of similar products. Compare to SeaKlear brand. Shelf life: indefinite. What in the world is Chitosan?