Sun Shield helps to protect chlorine in pool water from dissipation caused by sunlight. Intense sunlight causes difficulty in maintaining chlorine residual. DIRECTIONS FOR USE:Please read all precautionary statements and directions before using this product.  Check the stabilizer level at least once per month, more often for salt water pools. Do not exceed 100 ppm as chlorine effectiveness can be reduced.  The ideal range for a non-salt water pool is 20-25 ppm.  The ideal range for a salt water pool is 60 to 80 ppm.BEFORE ADDING THIS PRODUCT TO YOUR POOL  Clean and backwash the filter.  In non-salt water pools adjust free available chlorine level to 1-3 ppm with a  shock treatment, follow directions on that product label.  Measure the stabilizer (cyanuric acid) concentration with an appropriate test kit or test strip. HOW TO ADD THIS PRODUCT TO YOUR POOL Determine dosage of this product from the table below. With circulation pump on, add this product slowly to the skimmer.  Be careful not to overload the skimmer. Leave the circulation pump running and do not backwash for at least 48 hours. Ensure product is fully dissolved. Retest the stabilizer level after 48 hours and repeat treatment as necessary until stabilizer is in the ideal range.   Pool Volume   10 ppm   20 ppm   30 ppm   10,000 Gallons    1 lb   2 lbs   3 lbs   20,000 Gallons    2 lbs   4 lbs   5 lbs   40,000 Gallons   4 lbs   7 lbs   10 lbs