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How to Close a Pool for the Winter

July 28, 2021

If you live in an area with four seasons, you can enjoy your swimming pool for part of the year. But once the air starts to turn cool, and winter begins its approach, going for a dip in the pool holds less appeal. Since few people want to go swimming in the winter, and the water is likely to freeze when temperatures drop, you’ll want to close your pool for the season. Closing your pool properly keeps it in good condition during the off-season and makes it easy to reopen once temperatures climb again.

In this guide, we’ll be discussing how to close a pool properly for winter. Whether you have an aboveground or inground pool, these pool closing tips will protect it from the winter weather and save you time and money in the long run.

The Importance of Closing a Pool Properly

Although it might seem like a lot of work to prepare your swimming pool for winter and cover it, it actually ends up being less work for you in the long run. Winterizing and closing your pool helps to keep it in good condition during the winter. Here are some reasons why it’s worth the time to close your pool:

  • Keep debris out: Whether you have an aboveground or inground swimming pool, debris has a way of falling into it. Leaves, insects and, in some cases, small animals can find their way into the water. Some debris isn’t a big deal in the spring and summer, as you can skim it out when you go for a swim. But in the winter, when you aren’t using the pool, the debris is likely to collect and rot unless you cover things up.
  • Prevent parts from freezing: If you live in an area that experiences freezing temperatures in the winter, the cold weather can damage parts of your pool unless you take the time to winterize them. Water that freezes in the pipes or drain lines puts stress on the lines, potentially causing them to fail prematurely.
  • Keep the water balanced: The water in the pool should remain balanced through the winter to prevent damage to the pool walls and minimize algae growth. Covering the pool helps keep out snow and rain, which might be more acidic than you want the water in the pool to be. Maintaining the water’s balance also keeps the water’s minerals at the appropriate level. When there isn’t enough of a certain mineral, such as calcium, in the water, it can pull it from the pool’s walls, speeding up deterioration.
  • Prolong the life of your pool: Like any other appliance or fixture in your home, taking good care of your swimming pool means it will last longer. If you neglect the pool and leave it open all winter, it’s likely to wear down more quickly than if you take the time to winterize and cover it. Winterizing your pool can prevent issues such as the pool popping out of the ground or the joints and seams becoming cracked or loose.
  • Get back in the water sooner: Would you rather spend a few hours in the late fall getting your pool ready for winter or a few hours in the late spring cleaning up the pool before you can go swimming in it? Winterizing your pool protects it from debris and damage over the winter, allowing you to get back into the water sooner once the weather warms up again.



When Should You Winterize Your Swimming Pool?

Timing matters when winterizing your pool. If you start the process too early, algae can grow in the water, making more work for you. If you wait too long, cold temperatures can cause discomfort to you when closing the pool and can increase the risk of damage to the pool.

The standard recommendation for people who live in four-season areas is to wait until the temperatures have consistently dipped below 65 degrees Fahrenheit to start the winterization process. Algae thrive in warmer temperatures, so if you try to winterize too early, or when the weather is still warm, you risk having algae take over. Depending on your location, you can start the winterization process as early as August or as late as November. If temperatures never really fall below 65 degrees Fahrenheit, you can skip winterizing.

While you want to wait until the weather is cool, you don’t want to wait until it’s too cold. If there’s a risk of a frost or freeze, the cold can damage the pool parts. Not to mention, it can be unpleasant to have to work on a pool when the temperatures are hovering around 35 degrees or so.

Pool winterization is a multi-step, multi-day process, so be sure to give yourself enough time to prepare the pool and cover it before a frost arrives. Once you’ve seen several days of temperatures below 65, you can get started. The process might take a couple of days to a week.

How to Close a Swimming Pool for the Winter

While there is some overlap between how to close an inground pool and an aboveground pool for winter, there are some key differences. The first few steps of the winterization process are the same for inground and aboveground pools, and things diverge from there.

Clean the Pool and Balance the Water

Whether you have an inground or aboveground pool, the first step when winterizing it is to give it a good clean. You don’t want to put your pool away for the winter with leaves and debris floating in the water or with a thin coating of sediment on the surface. Instead, follow these steps to get your pool clean:

  • Skim the water: Use a skimmer to remove any large pieces of debris from the water, such as leaves, trash or sticks.
  • Brush the pool: Once you’ve removed the big pieces, use a pool brush to scrub the walls and floor of the pool, loosening up any dirt. Also, brush the steps of the pool and any other surfaces beneath the water. Brushing the pool can also help keep algae in check, as the friction stirs up and removes spores.
  • Vacuum the pool: After you’ve brushed the pool, vacuum it to suction away any stirred-up debris. You can use a manual pool vacuum or a robotic one. A robotic vacuum makes the work easy, while a manual vacuum allows you to be as thorough as possible.
  • Clean the deck: Once you’ve cleaned the pool’s interior, consider giving the deck a good cleaning, too. Depending on the size of the deck, you can manually clean it with a brush or use a pressure washer to blast away dirt and grime, directing it away from the pool.

After cleaning the pool, it’s time to balance the water and get it ready for several months without use. You want to ensure the water is at the right pH level and that it has enough sanitizer in it to get through the winter.

The first thing to do is test the water. You can use at-home testing strips or send out a sample to a lab. When testing the water, look for the following:

  • pH level: Between 7.2 and 7.6
  • Alkalinity: Between 80 and 150 parts-per-million (ppm)
  • Calcium hardness: Between 175 and 225 ppm
  • Chlorine levels: Between 1 and 3 ppm.

If the water doesn’t fall within the levels specified above, you’ll need to adjust it. The products you use depend on your goals. If there’s too much calcium in the pool, you’ll want to use a sequestering agent to lower the calcium hardness level. If there isn’t enough calcium, you’ll want to use a hardness increaser. To adjust the pH, you’ll need to add a base to increase it or acid to decrease it.

Once you’ve adjusted the pool water, shock the pool, then test the levels again a few days later. You might need to make further adjustments to balance the water before covering and closing the swimming pool.


Clean the Filter and Pool Equipment

Another part of winterizing a pool is cleaning the filter and any other equipment. Whether you have an inground or aboveground pool, how you clean the filter depends on the type:

  • Sand filter: Use a filter cleaner designed for sand filters or backwash the filter to remove debris. Set the valve to winterize and let the filter drain. On an aboveground pool, remove the filter and store it indoors over the winter.
  • Cartridge filter: You can rinse the filter to remove any gunk or use a filter cleaner. Let the filter dry completely, then store it indoors for the winter.
  • Diatomaceous earth filter: Clean the filter with a diatomaceous earth filter cleaner or rinse it well with water to remove any gunk. Once dry, store the filter indoors.

Along with cleaning and draining the filters, make sure you clean and drain any other equipment, such as a pool heater, the skimmer basket and the pump.

Turn off Pool Equipment and Store Accessories

Turn off any pool equipment you won’t use during the winter, such as a pool light or heater before you close it. Also, make sure any accessories, such as a pool thermometer, removable ladders and pool toys are cleaned and stored properly for the winter. Wipe down pool floats before deflating them, then store them indoors in air-tight containers for the winter.

Lower Water Level

You might need to lower the water level in your pool if you live in a climate that has freezing winters. Draining the pool slightly will prevent freeze damage. Whether you need to drain the pool or not also depends on the type of pool and the type of cover you have. With an inground pool, it’s important to lower the water level to just below the bottom of the skimmer or the tile line.

You might not have to lower the water level with an aboveground pool if you use a winter skimmer plate. Otherwise, reduce the water level to just below the edge of the skimmer.

Since different cover types specify different water depths, check the instructions that came with your pool cover to find out exactly how low your pool’s water level should go.


How to Winterize an Inground Pool

If you have an inground pool, there are some additional steps to take to get it ready for the winter, mainly blowing out and plugging the plumbing lines.

Freezing water puts pressure on pool plumbing, and most pools are designed to withstand that pressure. To keep them intact during the winter, you need to remove the water from the lines before a freeze. Since this step can be delicate and there’s a risk of damaging your pool’s plumbing if you use too much force, you might consider hiring a professional to take care of it for you.


How to Winterize an Aboveground Pool

Winterizing an aboveground pool involves these additional steps:

Clear and Store the Lines

You don’t have to blow out or plug plumbing lines for an aboveground pool. Instead, you should clean and remove the lines before it freezes. After cleaning the lines, allow them to dry completely before you put them away. If you store the lines when there is still some water in them, mold can grow over the winter.

Insert an Air Pillow

Over the winter, water and ice can collect on the pool cover, putting pressure on the sides of the pool. An air pillow, or ice compensator, makes up for the water and ice pressure, protecting the walls of your aboveground pool. Even if you don’t have to worry about freezes or ice, using an air pillow is still a good idea, as it can keep water and debris from pooling in the middle of the cover.


Cover the Pool for Winter

The last step when winterizing your pool is covering it. A pool cover keeps debris, bugs and small animals out of the water. It also keeps snow and rainwater from mixing with the pool water. Winter Block pool covers also block the sun’s ultraviolet rays, keeping algae growth to a minimum.

When covering your pool, there are some things to keep in mind. First is the pool type and size. The cover needs to fit your pool and shouldn’t be too large or small. Also, it’s important to make sure you use a cover made for the type of pool you have. An inground pool cover won’t adequately protect an aboveground pool, for instance.

If you have children or pets, consider using a pool safety cover instead of a Winter Block pool cover. A safety cover keeps out debris and bugs and prevents rainwater and snow from getting into the pool, as a Winter Block cover would. It also provides an additional layer of protection, as it won’t give way if a child or critter walks on it.

After covering the pool, you might want to check on it from time to time over the winter. Use a broom to sweep any debris off of the winter pool cover. Alternatively, you can put a mesh leaf net over the pool cover to catch this debris and make it easier to remove.

Pay attention to what you put on the cover, too. You can use water bags to hold it in place around the pool’s edges, but it’s best not to put heavy objects, such as bricks or stones, in the middle of the cover.

Winterize Your Pool With Products From SPQ Brands

Covering your pool is the last step in the winterization process. SPQ Brands produces high-quality winter pool covers that will protect your inground or aboveground pool all winter long. Contact us today to learn more about our winter pool covers and other pool products. You can also find our products at several top retailers.