09/18/2026
Everything You Need to Know About Winterizing Your Above Ground Swimming Pool
While it’s fun to live it up splashing around and enjoying your pool with family and friends, that time sadly comes to an end each year for the majority of swimming pool owners.
The long, warm days fade and get replaced with colder temperatures, falling leaves, and eventually, snow and ice. When fall comes around, and your pool water is consistently below 65*, it’s time to close up shop for the year.
Understanding how to properly winterize your AG swimming pool is essential. It helps prevent costly damage and greatly reduces the time it takes to open your pool in the spring.
Follow the below steps to winterize your above ground pool and close it for the season.
What You’ll Need to Winterize Your Pool:
Winter pool cover
Water test at a reputable pool store
Pool vacuum
Hose
Equipment instruction manuals
Scrubber/scrub brush
Winterizing chemical kit
Winter pillow(s)
Steps to Winterize Your Pool
Once you’ve gathered the supplies, it’s time to start the process of closing your pool for the winter.
1. Test and balance the water.
Several days before you close your pool for the season, you’ll want to test your water. Making sure your water is at the proper levels will help you avoid buildup, corrosion, and other damage to your pool and make opening your pool easier come spring.
When closing your pool for the winter, make sure your pool levels are as follows:
pH between 7.2 and 7.6.
Alkalinity between 100 and 120 ppm.
Calcium hardness between 200 and 250 ppm.
Chlorine between 2 and 4 ppm.
2. Clean your pool.
To avoid any nasty surprises come spring, you’ll also want to make sure your pool is as clean as possible before closing it up for the winter season. The cleaner, the better!
Start by cleaning up leaves, rocks, and debris around your pool that may end up in the water or present a tripping hazard.
After that, you’ll want to tackle cleaning the pool itself. Scrub your pool to remove any dirt and debris from your liner, then vacuum it thoroughly.
The busy pool season can take a toll on your liner. As you’re cleaning your pool, check your pool liner for signs of leaks or damage before going through the winterization process. If you notice any issues, you should repair or replace your liner before moving forward.
While you're at it, it's also a good time to clean off your patio area as well.
For more helpful tips for cleaning your pool, you can check out these resources:
9 Easy Pool Liner Cleaning Tips Every Owner Should Follow
How to Sanitize your Pool, Patio, and Pool Accessories
Note: The end of the season is a great time to have your pool professionally cleaned if you haven’t done so throughout the warm season. Professionals have the equipment and expertise that can get your swimming pool as clean as possible and help you spot any issues before closing it up for the season.
3. Add winter chemicals.
After your pool is thoroughly cleaned, it’s time to add the winter chemicals to the water. We recommend a winterizing chemical kit, which is a convenient way to get all of the chemicals you need for closing your pool all at once.
The ideal winter chemical kit contains a winterizing algaecide and chlorine or non-chlorine shock. It is also recommended to use a winterizing kit that comes with a metal control if you have a heater or use well water.
Once you have your kit, be sure to read and follow the instructions. Oftentimes, larger pools require additional algaecide or pool shock, which can be purchased separately as needed.
If you don’t opt for a winterizing kit, you should purchase the shock and algaecide recommended for your pool size. Follow the instructions on the back of the bottle and add it to your pool.
You can use either standard or fast-dissolving shock. When using standard shock, add it to the pool the night before you want to close it for best results.
Let the pool pump run for at least one complete cycle after adding chemicals. This is usually 4-8 hours. You should then backwash or manually clean the filter.
Pro tip: Don’t add algaecide and shock at the same time. The chlorine can oftentimes prevent the algaecide from working properly.
4. Winterize your pool pump and filter.
To winterize your pump, remove all drain plugs and hoses. Be sure to review and follow the instructions in your owner’s manual for your specific product.
Once removed, place all drain plugs in a pump basket for storage so they’re all together and don’t get lost in the shuffle.
Next, you have to winterize your filter. How to do this depends on what type of pool filter you have.
If you have a sand filter:
Set your multiport valve to winterize.
Let the filter completely drain out.
If necessary, remove the bleeder valve and sight glass.
Backwash your sand filter.
If you have a D.E. or cartridge filter:
Drain the filter.
Spray with cleaner.
Rinse with a hose.
Leave the valves open.
Plug the returns and any other outlets, and then remove all hoses from the filter, return, and skimmer. Once your filter and pump system are clean and disconnected, you should store your equipment indoors.
5. Lower the water level.
Next, lower the water level to approximately 4 to 6 inches below the skimmer. Be careful during this process.
Pools that are drained down too low can cause a lot of undue stress on the pool cover and liner, shortening their lifespan and costing you money.
Note: It’s very rare that you should ever need to completely drain your above ground pool. Doing so can cause damage to your liner. If you need to completely drain your pool, consult a professional.
6. Remove, clean, and store removable parts and equipment.
Now, it’s time to take care of all those extra pool parts and accessories. Take time to remove all non-permanent pool parts, such as ladders, pool stairs, floats and toys, etc.
Rinse all these items off with a hose and use bleach or a non-chemical cleaner (like vinegar) to remove dirt, debris, and bacteria. Let them dry completely before putting them in storage to prevent mold, mildew, and rust.
You can learn more by reading our tips for cleaning swimming pool toys and floats.
As you’re putting all your parts, accessories, and equipment away, check for any signs of damage. That way, you can repair it or make a note that it needs to be replaced and avoid any surprises when opening your pool next season.
Oftentimes, if something needs to be replaced, you can score good deals at the end of the outdoor pool season.
7. Inflate and place an air pillow.
Winter Air Pillow
Winter pillows aren’t 100% necessary, but some people like them.
Air pillows help protect your pool by evenly distributing the water that collects on your winter cover and pushing it toward the edge of the pool, making it easier to remove. It also causes ice to crack, which helps relieve pressure on your pool and prevents structural damage
For peak effectiveness, the pillow should be placed in the middle of the pool. Depending on the size of your pool, you may need multiple pillows. If so, tie them together using the grommets on the corners.
8. Put on the winter cover.
Once the winter pillow is in place, you can put your winter pool cover over the top of your pool.
Here’s how to put a winter cover on an above ground pool:
Place the cover on the pool. Make sure it is centered over the air pillow and even on all sides. You may need a friend or family member’s help here.
Secure the cover. Once it is in place, secure it by using a cable and winch, water bags, or a combination of winter cover clips and a cable. The cover should be tight and not sag. Avoid using heavy weights like concrete blocks and bricks. They could cause damage to your cover or your pool.
After the cover is secured, you may want to run a winterizing cover wrap around your pool to seal it and prevent the cover from moving, flapping, or coming off.
9. Check your pool regularly.
Your pool should now be set for the winter. However, you should remove snow and debris from your cover and check in on your pool regularly throughout the cold season.
Checking in on your pool will help you spot any issues or damage before it’s too late. Look for common winter problems like:
Cracks and indentations in your pool’s walls (from ice expansion)
Ice build-up inside your swimming pool
Holes in your winter pool cover
Cracked or broken equipment (often caused by freezing)
Algae buildup
*borrowed from LinerWorld.com
