The Mineral Stick™ helps to naturally keep hot tub water fresh and clean. The unique formula releases a combination of copper, silver and zinc ions that result in cleaner, softer-feeling water. It can reduce the amount of chlorine or bromine you use by up to 50%, helping to cut down on unpleasant odors and skin irritation. Charcoal beads also help filter oils and scum out of the water, resulting in a fresher, cleaner tub.