The mineral ion cartridge brings you clean, crystal-clear spa water without high levels of heavy chemicals. The active ingredient is zinc. (The inert ingredients are vitamin C, calcium sulfate, zeolite, attapulgite clay, zinc oxide, and magnesium oxide.) A difference you can see, feel, and smell, the spa mineral cartridge improves water quality. Easy to install and low maintenance, compatible with most spa maintenance products. The mineral filter stick is a simple option for you, enjoy your relaxing spa experience with peace of mind. Mineral ion controlled release technology, automatically dissolving trace mineral elements in the water. Mineral Stick works with the existing filtration system, designed to fit most spa and hot tub filters, available for 24-hour flow rate.