How to Winterize an Above-Ground Pool in 8 Steps

Take the plunge into winter pool prep

Gemma Johnstone
Written by Gemma Johnstone
Updated August 1, 2022
ind_tips_pools
Photo: Courtesy of Kevin S.
Difficulty

Simple

Saturday skill builder.

Time to complete

4 hours

Cost

$100–$200

Make room—this DIY requires a lot of supplies!

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What you'll need:

TOOLS

  • Skimmer plate
  • Pool air pillow
  • Pool cover
  • Leaf rake or skimmer net
  • Pool brush
  • Pool vacuum (optional)
  • Bucket

SUPPLIES

  • Pool testing kit (chlorine, alkalinity, pH)
  • Algaecide
  • Shock (chlorine or non-chlorine)
  • Winterizing pill
  • Stain and scale remover (optional)
  • Baking soda (if alkalinity needs increasing)
  • Calcium chloride (if calcium harness needs increasing)

An above-ground pool is the ultimate family-friendly hang-out space. There’s nothing better than being able to take a dip on a hot summer’s day. But when the weather turns chilly, it’s time to winterize your pool.

If you leave your pool unprotected, you could have a sinking feeling next summer. Weather-related damage, pollutants, and dirt can wreak havoc on your dormant backyard oasis. Learn how to winterize your above-ground pool to protect your investment and keep the pool parties in play when the warm weather returns. 

Prepping to Winterize Your Above-Ground Pool

The list of supplies might seem long, but you probably already have some items in your garage or garden shed for general year-round pool maintenance. Check what you already have and decide what you need to buy so you can get cracking before the cold weather arrives.

Before you start the winterization process, it’s time to deflate your fun floats and remove all the other pool accessories (including the ladder). Give everything a good clean, let them fully dry, and store them in a dry spot out of direct sunlight.

  1. Deep Clean Your Pool

    Hopefully, you’ve kept on top of pool cleaning duties throughout the swimming season. That way, winterizing your above-ground pool won’t be too arduous a task. You can add scale and stain remover a couple of weeks before you start the job. 

    Gently scrub the sides and base of the pool with a pool brush and get everything off the floor (use a pool vacuum if you have one). Use a leaf brush or skimmer net and be meticulous about lifting debris from the water surface. The cleaner you leave the pool, the less chance of algae growth building during the winter.

  2. Test the Water Chemistry

    Using your testing kit, check the pool water chemistry and adjust as appropriate. 

    Aim for the following: 

    • Alkalinity concentration between 80–120 parts-per-million (ppm) 

    • pH level between 7.3–7.6

    • Calcium hardness between 175–225 ppm (for a vinyl or fiberglass liner)

    • Chlorine (if you use this for cleaning) between 1–3 ppm

    Plumping for the higher end of the ranges means the chemical balance lasts better through the winter.

  3. Add Shock and Algaecide

    Shocking your pool sounds dramatic, but it's simply the name given to the process of adding a specific chlorine or non-chlorine chemical pool product to raise the free chlorine level. This helps get rid of pesky chloramines, bacteria, algae, and other contaminants that make your pool cloudy and unsanitary.

    You should already be familiar with the process, as it's done regularly throughout the summer as part of ongoing pool maintenance. But it’s also an essential step in winterizing your above-ground pool. 

    Always follow the manufacturer guidelines for application and dosage volumes. For a very dirty pool, you might have to shock it two or three times to maintain safe chlorine levels. If you're concerned about algal growth, you can also add an algaecide, but check whether it's safe to use this alongside your shock treatment. 

    Alternatively, lift the cover of your pool every few weeks during winter and if you see any signs of algae growth, add the algaecide then.

  4. Lower the Water Levels or Protect Your Skimmer

    An above-ground pool skimmer hangs on the side of the pool, just submerged in the water. It pulls water through the basket, filtering off dirt and debris. If you invest in a winter skimmer plate, remove the hose, drain the skimmer, and fit the plate. This prevents freezing and cracking without you having to change the water levels.  

    Don’t want to invest in the skimmer plate? Lower the water levels using a hand siphon or pump to 4 to 6 inches below the skimmer. Just don’t drain your pool fully. This dries out the vinyl liner, decreasing its lifespan.

  5. Drain Equipment

    Water in the lines, pumps, or filters continually freezes and thaws during a hard winter. This expansion can damage the equipment. To avoid this and unsanitary mold growth, drain away the water, thoroughly dry the items, and then store them in a dry spot. 

  6. Add Winterizing Pill (Optional)

    Floating, conditioning winterizing pills help to inhibit scale and stains and clarify the water. They’re not an essential item, but they won’t break the bank. Also, they’re simple to use and they last right through the winter. 

  7. Install an Air Pillow

    When ice or snow builds up on top of your pool cover, it presses against the water and gets stuck when it freezes over. Using an air pillow in the middle of the water surface, or a few if you have a large pool, prevents ice from expanding outwards. You’re less likely to have ice creating damaging pressure on the pool walls.

  8. Cover the Pool

    You don't want your pool to fill up with leaf litter and other debris over the winter, so fitting a snug, secure cover is a must. 

    A well-fitting pool cover (steer clear of flappy tarps) stays on regardless of the weather, so don't weigh it down with something like a brick. This is more likely to damage the cover and possibly even the pool. After a big dump of snow, take the time to clear any piles off the cover.

DIY Winterizing Your Above-Ground Pool vs. Hiring a Pro

Although winterizing your pool doesn't involve anything too technical, there are multiple steps. Plus, if you miss a step or (just don’t do it), there may be some disappointment come summer if the pool suffers from freeze damage or algae buildup. 

If you’re worried about balancing the water chemistry or you’d rather free up an afternoon, hiring a professional pool cleaner near you offers convenience and peace of mind. 

Expect to pay $150 to $300, which includes the cost of the chemicals. To budget for swimming pool maintenance costs, it’s helpful to know that pros typically charge $50 to $100 per hour.

You’ll still have to invest in cleaning and balancing supplies if you do it yourself, but you could save $50 to $150 (or more if you bulk buy some chemicals).

Additional Questions

When should I winterize my above-ground pool?

If you’re lucky enough to live in a region with year-round balmy temperatures, you won't have to worry about winterization. Keep an eye on the forecast—you want to take action before the temperatures start dropping below 65 degrees Fahrenheit. 

What is different about winterizing an above-ground pool compared to an in-ground pool?

Above-ground pool winterization usually involves less hassle, time, and expense than the process for an in-ground pool. All the lines are easy to access, making draining easier. Plus, above-ground pools are typically smaller, meaning cleaning is quicker, and chemicals cost less.

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Get quotes from top-rated pros.