Pool Closing

Winterizing an In-Ground Pool for Non-Freezing Conditions


As the summer winds down, it is time to start getting your pool ready for the cold winter months. Properly winterizing your pool will protect your equipment from ice damage, keep your water clean, and will help save you time and money when opening your pool in the spring. Winterizing your pool may seem complicated, but with a little preparation, it can be a very simple and pain-free process. Leslie’s has compiled a set of step-by-step instructions to help you safely and effectively winterize your pool.

If you live in a climate that rarely has temperatures dip below freezing, and you own an in-ground pool, follow these easy-to-follow instructions to help you close your pool at the end of the season.

  1. One week prior to closing your pool, add 14 fluid ounces of Pool Magic + PHOSfree for every 10,000 gallons of water directly into the skimmer.
  2. Brush and vacuum the pool thoroughly to remove all dirt, leaves, and debris.
  3. Fill the pool to the top, almost to the point of overflowing.
  4. To prevent metal stains, add MetalFree and Leslie’s Stain and Scale 2. For every 20,000 gallons, add one liter of MetalFree and one quart (32 ounces) of Leslies Stain and Scale 2 by pouring it around the perimeter of the pool.
  5. Adjust the Total Alkalinity to the proper level. Total Alkalinity should be in the 80 – 120 ppm range for plaster pools, and in the 120-140 range for vinyl-lined pools. To easily adjust Total Alkalinity, use Leslie’s Alkalinity Up by broadcasting it around the perimeter of the pool. Just one pound of Leslie’s Alkalinity Up will increase the Total Alkalinity of 10,000 gallons of water by 10 ppm.
  6. Adjust the pH to the proper level. For all pools, the pH should be between 7.4 and 7.6. Leslie’s Soda Ash quickly raises a pool’s pH. Just 6 ounces raises the pH level of 10,000 gallons by 0.2. For plaster pools, broadcast it around the perimeter of your pool. For vinyl-lined pools, mix it with water in a large bucket before adding it to your pool.
  7. To help protect your pool, adjust the Calcium Hardness to 200-400 ppm using Leslie’s Hardness Plus. Adding 1 ¼ pounds of Leslie’s Hardness Plus for every 10,000 gallons of water will increase the Calcium Hardness by 10 ppm.
  8. Add one quart (32 ounces) of Leslie’s Algae Control per 25,000 gallons by mixing it with water in a large bucket and then pouring around the perimeter of your pool. Wait one hour before following the next step.
  9. Shock the pool with Leslie’s Fresh ‘N Clear at the rate of two pounds per 10,000 gallons by broadcasting the product around the perimeter of your pool.
  10. Bring the chlorine to an appropriate level – between 1.5-3.0 ppm.
  11. Let the pump run for at least one complete cycle after adding chemicals. This is usually 4-8 hours. Backwash or manually clean the filter.
  12. Set the time clock to run the filter for 2-4 hours per day.
  13. Cover the pool using a Safety Cover or Winter Cover and Leaf Net.
  14. If necessary, fill and place Water Bags or Hold-Em-Downs around the edge of the pool. In normal conditions, these can be placed 18 inches apart, but in windy areas, they should be placed end-to-end.
  15. During the winter season, check the chemical balance every two weeks, and inspect the pool water by pulling back the cover slightly. If staining or scaling is beginning to develop, bring a sample of your water into your nearest Leslie’s location.

If you have any questions about how to properly prepare your pool for the winter months that were not answered above, please visit your local Leslie’s store or call 1-800-LESLIES for more information.