Winterizing an Above-Ground Pool for 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 will see long periods of freezing temperatures, and you own an above-ground pool, these easy-to-follow instructions will 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 + PHOSfreedirectly into the skimmer for every 10,000 gallons of water.

2. Brush and vacuum the pool thoroughly to remove all dirt, leaves, and debris.


3. 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 your pool.


4. 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 perimeter of your pool. For vinyl-lined pools, mix it with water in a large bucket before adding it to your pool.

5. Adjust the Total Alkalinity to the proper level. Total Alkalinity should be in the 80 – 120 ppm range for plaster pools and the 120-140 range for vinyl-lined pools. To easily adjust Total Alkalinity, use Leslie’s Alkalinity Up by broadcasting 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. To help protect your pool, adjust the Calcium Hardness to 200-400 ppm using Leslie’s Hardness Plus. Adding 1 1/4 pounds of Leslie’s Hardness Plus for every 10,000 gallons of water will increase the Calcium Hardness by 10 ppm

7. Add one quart (32 ounces) of Leslie’s Algae Control per 25,000 gallons by mixing it with water in a large bucket and pouring it around the perimeter of your pool. Wait one hour before following the next step.


8. 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.


9. Bring the chlorine to an appropriate level – between 1.5-3.0 ppm.

10. 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.

11. Remove the inlet (directional or eyeball) fitting, which is located on the inside pool wall, usually 6″ to 12″ below the water line. Insert a winterizing plug into the inlet.

12. Lower the water level to between 4″ to 6″ below the skimmer.

13. Remove the drain plugs from the pump strainer basket housing, the pump volute, the filter tank, and the heater. Keep the drain plugs handy, they will be used in Step 17.

14. Disconnect the filter hoses from the skimmer fitting and the pool return fitting.

15. Drain the automatic chlorinator, if you use one.

16. Move all the equipment you removed to a safe and non-freezing location, such as your basement.

17. Place all the drain plugs in the strainer basket of the pump and replace the strainer cover.

18. Remove all non-permanent articles such as ladders, hoses, over-the-top skimmers, etc. If you have an automatic pool cleaner, remove it and drain it completely. Lay the hoses out straight in a non-freezing location.

19. Inflate and tie Air Pillows to a stationary object. An average-sized pool, 18′ x 18′, typically requires 2-3 air pillows. If you are using multiple pillows, tie them together using the grommets located on the pillow’s corners.

20. Cover the pool using a Safety Cover or Winter Cover and Leaf Net. This may require the use of a cable and winch.


21. If necessary, use Above-Ground Wall Bags to secure the cover.

22. During the winter season, check the chemical balance every two weeks using a test kit 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.