Arctic Pure Adjust Up raises the pH levels in your spa water. Recommended range of pH levels is 7.2 – 7.8, when the pH falls below 7.2, the water becomes acidic causing skin discomfort and eye irritation. Low pH levels also cause chlorine levels to become unstable, and therefore less effective in eliminating bacteria, algae and other organic matter. Arctic Pure Adjust Up is readily soluble in water and can simply be broadcasted over the water surface. Your spa water is safe to enter immediately after adding Adjust Up.