How to Close or Winterize Your Above Ground Swimming Pool

Above Ground Pool Cover with Air Pillow in Middle

Above Ground Pool Cover with Air Pillow in Middle

A Step-by-Step Guide to Close your Above Ground Pool for the Winter

Step 1

Before closing your above ground pool, make sure the water is clean, clear and chemically balanced.  Adjust the chemical levels if necessary.  Chemically balanced water protects the pool from corrosion or scale buildup that can occur while the pool is not in use. Your chemical levels should be as follows:

  • pH: 7.2 – 7.6
  • Alkalinity: 80 – 120 parts per million
  • Calcium Hardness: 175 – 250 parts per million
  • Chlorine: 1 – 3 parts per million

Step 2

Remove all deck equipment, including ladders, stairs, etc.

Step 3

Brush down the sides and floor of your pool and then vacuum. This step prevents staining, which can occur if any dirt or debris is left to sit in the pool.

Step 4

Add winterizing chemicals by broadcasting them into the deep end of the pool. These chemicals help protect water quality during the off season months.

Step 5

Clean the filter, skimmer, and pump basket. Remove all unused chlorine product from the chlorinator. Cartridge filter elements and D.E. grids should be cleaned and stored.  If you have a sand filter, backwash it.

Step 6

Some people insert a skimmer guard into the skimmer and plug the return line. Others lower the water in the pool below the returns (where the water jets into the pool) and the skimmer. Either method is fine — the choice made is based on personal preference.

Important: Never completely drain an above ground pool. This can cause your pool to collapse.

Step 7

If your pool is plumbed with detachable, flexible hoses, remove them and store for the winter. Remove all drain plugs from the pump, filter tank, and any other pool equipment. Follow the manufacturer’s instructions for your specific pump, filter and other equipment.   Basically you’ll need to drain them so there is no water in them that could freeze and damage the pump or filter.     Place all drain plugs in the pump’s basket for storage and so you won’t loose them.

If your pool is hard plumbed, use an air compressor or shop vac (attached to the blower side of the vac) to blow water out of the system by forcing air down the skimmer and through the plumbing.

Step 8

If you are using an air pillow,  inflate it by using a shop vac.  Tie the air pillow at two places and position it in the center of the pool.  Tie strings to the pool wall so the pillow will not move during installation of the pool cover.  Air pillows are commonly used, but not absolutely necessary.  They are a good idea in colder climates in case the water freezes and expands.  The water will freeze inwards on the pillow instead of outwards which can potentially damage the pool wall.   Pillows are NOT used to create a dome-like effect to keep rain off of the cover.  Rain water will always settle around the pillow.

Step 9

Place an winter cover over the pool surface, black side down.  Some homeowners who have children or pets and have a deck with at least 3 ft of deck space all the way around their pool may prefer to cover the pool with a safety cover over the winter.

If covering your pool with a winter cover,  place the cover over the pool,  then thread the cable through the loops or grommets.  Use the winch provided with the cover to tighten the cable.   The cover should rest directly on the water and go up and over wall and back down on the outside of pool.

If your above ground pool has a deck, place water tubes end to end around the edge of the pool. Fill the bags 3/4 full with water.  Do not over-fill because the bags could burst when the water inside freezes.  Never use bricks,  concrete blocks, etc. to secure the cover because they can damage your pool cover or your pool.

Step 10

Place a cover pump in the center of your pool cover to drain excess water accumulation.  Too much water on top of the cover can cause the cover to rip, or it can pull the cover and wall bags into the pool.  Either way, you’re in for a messy cleanup effort.

Now you are ready for the winter!


About Trey Collier

Grew up as a Military Brat. (Thanks Dad. Hats off to my Mom too as it took a special person to be married to someone in the military) Was a competitive swimmer in high school and in college. 11 years a Red Cross Volunteer, teaching kids & adults how to swim. ARC Water Safety Instructor and WSI Trainer, CPR Instructor/Trainer and Advance First Aid Instructor. Proud Dad of two beautiful girls.

37 thoughts on “How to Close or Winterize Your Above Ground Swimming Pool”

  1. Mary C.

    We live in Western Montana – winter temps hover around 20 degrees, sometimes a cold streak brings below zero weather. This will be the first year we try to winterize our 21′ AGP rather than take it down. This is the best advice I’ve found on winterizing an above ground pool in cold climates! Thank you!

  2. Carol

    I have an above ground pool with surrounding deck. For the winter cover do I still secure it with the wire and winch or can I use the water tubes on top of the deck?

    1. Trey Collier Post Author

      Decks can be built where they Top Rail is over the deck, the deck butts up level, or the deck boards are over the top rail. In most of these it is difficult to get the cover between the deck and the pool. This cover is best used this way. Putting the cover up on the deck and securing with water tubes allows air under the cover and its lifespan is greatly reduced and warranty is void with mfgs. When using tubes this will be better than without a cover, but not near as well as it was intended to be secured.

  3. vondeliusc

    Trey, we are installing an 18′ x 48″ AGP here in Kalispell, Montana. It usually gets down to 20* below zero for less than a week, and normally averages below freezing for months, with a typical average hovering around 15*-20*. Can you explain how that will not freeze solid; and we are planning on using an Intex saltwater system (with the pump/plumbing/salt system removed during the freeze. And how will the salted water fare compared to normal water?

    1. Trey Collier Post Author

      Given enough cold, it can freeze solid, Usually, the ice acts like a coat and insulates the inner/deeper water. Thats how people in Alaska can still fish from holes they make in lakes. Salt pools lower the freezing point of water depending on its saturation down to 27-22 degrees instead of 32 degrees (F)

      1. vondeliusc

        So is freezing solid a bad thing(should we worry)? What is your advice in the extreme cold situation (as far as standard winterization steps to protect the pool and us from worry)? I would hate for it to expand the typical 9% water does when it freezes and damage the pool.

  4. Michele Elizabeth Horn

    Is there plugs to get for the inlet and outlet hose holes? Didn’t know we had to undo the hoses and pump. Should pump be brought inside ?

    1. Trey Collier Post Author

      Yes there are. Can find them at local hardware cheaper than us shipping them. Even local < > pool stores too. 🙂 Need to drain pump/hose/filter if in areas where any ice can occur. No need to bring inside unless you really want to. TIP: all clamps, eye ball jets, and small items I’d put in the pumps’ basket for next spring.

      1. Mark James

        I have an intex 16×48 above ground. Once I remove the import and export hoses do I leave the actual pieces themselves in or do they come out as well? Leaving simply holes in side of pool during winter

  5. Dale Porter

    I am considering a 27 ft above ground pool but there are no winter covers for that size listed. Will a 28 ft pool cover work?

    1. Trey Collier Post Author

      If it is a solid cover only two things will let it sink! Lots of rain/snow melt water that you don’t adequately siphon/pump off, or you have holes in the cover and it needs to be replaced.

  6. Henry Cavendish

    The Step-by-Step Guide you presented is amazing. I love the way you described the things and I am going to do the same for my home. Thanks!

  7. Steve

    I have a dough boy 24′ and have left it running through the winter 6 hrs a day, 24 hours if there is a hard freeze. This year I am covering & using a 4″ plumbing test plug for skimmer, & a 1 1/2″ plug for inlet. And filling to top to lessen the drop for the tarp, I may use a pillow as well. Thoughts on plumbing test plugs ? ( wing nut type)

    1. Trey Collier Post Author

      Spend some time reading our blog posts and you’ll get most of your answers! I’d give you more specific link but dont know if you are Alaska, Detroit or Florida….as that would adjust our answers

  8. Janice

    Do I leave the sand filter and pump running when I add the winter chemicals? To let them circulate through the filter. Thanks

    1. Trey Collier Post Author

      As Snopes stated, there isn’t any substance that will discolor the water if urine or fecal matter is in the pool. Maintaining your pools’ sanitizer at the recommended rate will usually take care of this issue.

    1. Trey Collier Post Author

      Since the sanitizing system is a Salt Chlorinator and it provides the “Chemicals” from the salt in the water, turn up to HIGH and run for 2-3 days. Then add double the amount of algeacide to the water than what is normally recommended for your size pool. Then follow the normal closing procedures.

  9. John Ferre

    I have a grommet style above ground pool cover. Last year with the snow, it started concaving in the pool regardless of how tight i made the wire. Could I use rope or other and tie each grommet to an eye bolt in the ground or into the base legs on the outside of the pool to get the cover extra taut, with the pillow?

    1. Trey Collier Post Author

      Typical winter covers are designed to go down the side of the pool and rest on the water’s surface. The cover is then held in place with the water’s surface tension and minimizes movement of the cover when it windy. If your cover doesn’t have enough overlap to be secured in place with the wire/winch AND to go up, over and down to the pool’s water, across the water then up, over and down the other wall, then it is not big enough to be used as intended.

  10. Phil Elerick

    We have an above ground pool that we are going to replace the liner on next spring. DO we still winterize or drain the pool when we shut down this fall?

    1. Trey Collier Post Author

      Leave the water in the pool until you want to change your liner! The above ground pool is designed to hold against the outward force of the water. If you remove the water, 10mph winds or higher could bend the pool wall inward and now you’ll need a new pool wall.

      I would winterize the pool as normal. When it comes time to change the liner, do it on a day that isn’t windy. Drain pool, install new liner, and fill it up as quickly as possible.

Like it? Share It. Leave a Comment or Question below.