How to winterize a pool: A quick guide



During the warm summer months, a pool can be an amazing addition to the home. Swimming and relaxing in the backyard provides hours of relaxation, exercise and entertainment, even through the hottest parts of the summer. However, before the winter months, it’s important to winterize your pool. Proper maintenance can help protect your pool during the cold weather when the water freezes.  

Here’s what you need to know about winterizing your in-ground or above-ground pool after the summer season.


The importance of winterizing your pool

Properly winterizing your pool helps protect it and all the equipment involved in keeping it running. Freezing water can damage the equipment that keeps your pool clean and usable throughout the summer months. If ice freezes inside critical pool parts, it can cause cracks and leaks that lead to costly repairs when everything starts to thaw. Ice can even damage the vinyl liner around the pool. 

In addition to ice, sitting pool water that’s not actively filtered can grow bacteria and algae. If that happens, you’ll have to do a lot of work before you can use the pool again safely. 

So, the best strategy to protect your pool and your investment in this source of summer fun is to take the time to properly winterize it. We’ll walk you through the steps involved. 

When to winterize your pool

Timing is an important part of successfully preparing your pool for winter. As mentioned, allowing the water to sit without filters running can result in bacteria and algae growth. So, it’s a good idea to wait until the temperature consistently begins to drop below 65 degrees Fahrenheit. This reduces the risk of bacteria growth, but still gets the pool closed up long before it starts to freeze so you don’t risk dealing with ice.

Expect the pool winterization process to take you a few days to complete successfully. Plan on about a week to go through all the steps.


How to winterize your in-ground pool

We’ll walk you through the major steps involved in winterizing your pool. A proper pool closing can help make sure your pool remains usable, and you can limit freeze damage to the pool throughout the cold-weather months.

Deep-clean your pool

Begin by giving your pool a deep cleaning. You don’t want dirt or debris sitting in the pool throughout the winter, as this will only encourage the growth of bacteria and can end up staining your liners. Getting any dirt and debris out of the pool will also make it easier for you to ensure the pool’s chemistry remains balanced throughout the winter. 

Deep cleaning the pool involves using a skimmer to remove any debris, using your pool vacuum to clean the bottom, and brushing and scrubbing the pool walls. You also want to remove any accessories or extra equipment, such as skimmer baskets, ladders or steps.

Since cleaning the pool can be a bit of a hassle, you’ll want to make sure the pool remains covered once you complete this step. This will avoid more debris falling into the pool before it’s completely winterized.

Adjust the water chemistry

As any pool owner knows, pool chemistry plays a critical role in keeping potentially harmful bacteria away. You’ll want to use a test kit to measure your pool’s water chemistry. Depending on the test results, you may need to add pool chemicals. Use your winterizing chemicals to keep the pH levels between 7.2 and 7.6, the total alkalinity between 80 and 150 parts per million (ppm), the chlorine levels between 1 and 3 ppm, and the calcium hardness between 175 and 225 ppm. 

As you test your water and finalize your chemical balance, remember that the levels will naturally begin to decrease throughout the winter. So, it might be a good idea to aim for the higher end of each range. 

Adjust the water level and drain the equipment

Whether you need to lower your water level will depend on a few factors. If you don’t live in an area where the water will freeze over the winter, this might not be as important of a step. However, if you do expect ice — even if it’s just surface ice — you’ll want to lower the water level of your pool until it’s about a foot below the skimmer, assuming you have a mesh cover. If you have a solid cover, you can lower the water level by about 6 inches. 

As you adjust your water level, make sure to drain the water from your pool equipment so that freezing water doesn’t damage the components. This includes:

  • Clearing the water from the pool lines with a blower
  • Draining your pool filters and hoses
  • Draining your pool pump
  • Draining your heater

Many components come with drain plugs so that you can keep water out of them throughout the winter. You may also find it helpful to add pool antifreeze to the pool lines. If you have a filter and pump components that can be stored in a pool house or shed, stocking these parts inside for the winter is a good idea.

Add pool shock and algaecide

Next, measure and add pool shock to kill any bacteria, and add algaecide to kill any algae trying to grow in your swimming pool. The amount you need to add and how long you need to let it sit before you finish the pool-closing process will depend on the type and size of your pool. Read the instructions on the specific pool shock and algaecide you purchased for the best results. 

Properly cover the pool

Once you’ve finished the process of balancing, cleaning and caring for your pool, finalize the process by closing up the pool for the winter. The pool cover you choose will help to keep things from falling into the pool. If you have children, pets or live in an area with ample wildlife, a safety cover might be your best choice. These types of covers anchor down to the pool deck and help prevent not only debris but also animals and people from falling into the pool. You can also select a winter cover. A winter pool cover doesn’t provide as many safety features, but it helps keep debris out of the pool.

Keep in mind that if you have an above-ground pool, you’ll need to put in an air pillow before adding the cover. This will help keep the pool safe as freezing temperatures cause water expansion.

Regardless of the type of cover you choose, make sure it has been properly secured for the winter. This means ensuring the design fits your pool size and that it hasn’t been damaged, such as developing holes throughout the summer.


Keep other home systems protected in the winter with Cinch

Keeping up with your pool maintenance and taking the time to properly winterize your pool can help it serve you well for years to come. When the next spring arrives and it’s time to get ready for the swimming season, your pool will be ready for you. 

With your pool properly taken care of, you can focus on other built-in systems and major appliances in your home. Cinch Home Services makes it simple to handle unexpected breakdowns and repairs with a home warranty that won’t break the bank. Choose between three home protection plans — Appliances, Built-in Systems and Complete Home — and spend more time enjoying your home and less time worrying about it. 

Request a free quote today and enjoy everything your home has to offer.


Getting your pool ready for winter is an important process. Here’s what you need to do to protect your pool from damage.