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How to Winterize Inground Swimming Pools

By Caryn Anderson
Inground pools require proper winterization to prevent pipes from cracking when temperatures drop below freezing.
Swimming pool and pool house image by Jim Mills from Fotolia.com

As summer turns into fall, in many areas of the United States pool owners turn their thoughts to closing and winterizing the pool. Good technique along with proper supplies such as a pool cover, plugs, water tubes and winterizing chemicals are crucial to minimizing work to open the pool in the spring.

Balance the pool water’s chemicals. Three days to one week before closing your pool, use a testing kit to check the chemical levels. The water’s pH should be between 7.2 and 7.6; alkalinity should be between 80 and 150 ppm (parts per million) and the calcium hardness should be between 180 and 220 ppm. If necessary, adjust chemicals and retest the next day.

Locate winterizing supplies and ensure all materials are free of cracks or holes. Replace any items (water tubes, pool cover or skimmer plugs) that are damaged.

Brush pool sides, skim the water surface and vacuum the bottom. Be sure to remove all leaves and debris from the pool. Add shock to the pool. When winterizing an inground pool, chlorine levels should be above 3.0 to maintain water quality.

Backwash the pool filter and thoroughly clean all components. If the filter and pump are removable, clean both items, allow them to dry and store indoors. Otherwise, use an air compressor to blow all of the lines dry and ensure that there is no water left in the filter, pump or any other pool equipment which is stored outdoors. This is crucial to avoiding the plumbing lines from expanding in freezing temperatures and cracking.

Remove the fittings from all return jets and all skimmer baskets. Blow the return jet pipes dry using an air compressor or shop-vac. Keep air moving through the pipes until bubbles emerge from the pool’s return jets. Place a plug in the pipe’s fitting under the water.

Use the air compressor to blow the skimmer pipes and main drain lines dry. Keep air moving through the pipes until bubbles are visible. Tightly plug the pipes and main drain line to create an air lock, which prevents water from entering the line from the pool.

Wrap exposed pipes with duct tape and remove all floats, ladders and diving boards from the pool. Store pool items in a safe location.

Place the pool cover on the top of the pool. Attach water tubes through the cover’s loops. and fill tubes about 85 percent full before sealing. Secure pool cover so that it is tightly fitting with no gaps through which leaves or dirt can enter the pool.


Things You Will Need

  • Water chemical test kit
  • Pool chemicals (chlorine, alkalinity adjuster, algaecide)
  • Winterizing supplies (cover, water tubes, plugs)
  • Air compressor or Shop-vac
  • Duct tape
  • Water


  • Use a leaf net or mesh cover topper if your pool is surrounded by many trees. This will allow you to easily remove leaves from the cover before they weigh the cover down and cause sagging.


  • Avoid overfilling water tubes to allow enough slack for expansion. Otherwise, tubes will split when they freeze.

About the Author


Caryn Anderson combines extensive behind-the-scenes writing experience with her passion for all things food, fashion, garden and travel. Bitten by the travel bug at the age of 15 after a trip to Europe, Anderson fostered her love of style and fashion while living in New York City and earning her degree at New York University.