Pool Care Pool Opening and Closing

Winterizing an above Ground Pool in 10 Steps

Winterizing an above Ground Pool in 10 Steps

Winter is finally here with us. It’s hard to see you won’t be splashing around in your above-ground pool until next summer.

Now all you can do is get ready for the season. With the temperature dropping and tree leaves falling all over the place, your neighbor mowing the lawn, there’s no doubt summertime is ending.

And you know what, if you live in those cold areas that experience extreme winter, you will need to start thinking about how to winterize above ground pool.

Why Winterize an Above Ground Pool?

Fall gives us time to plan for the winter, and it’s at this time, we start winterizing things that cannot handle freezing well, including an above-ground pool.

If your above-ground pool is in an area with mild winters, there might be no need to consider closing it at all.

However, if your area receives freezing temperatures or you’re planning on closing the swimming pool for quite some time, months or so, it’s best to winterize it.

Some clear of the rugged winter season are frost, deep cold, and snow, which all go against the best conditions for an above-ground pool.

It would be best to prepare it by imposing the proper measures that protect it against all these winter ravages. It’s an essential step in ensuring your swimming pool stays in shape and ready for reopening during summer.

Effects of these conditions can be quite damaging significantly if the conditions deteriorate as months go by.

What’s more, an open, unused swimming pool can collect all kinds of debris that can overwhelm your pool skimmer and filter.

If the pool is left all open, you will have some serious work to deal with come spring. What’s more, you will have to deal with freeze damages and pool rebalancing.

Winterizing your above-ground pool reduces cold damages to your investment components. It’s a preventive measure to save you money, time, and also frustration.

When Should You Winterize Your Above Ground Pool

The need for a swimming pool depends on the climate of the area you live in and might vary in the closing times. The rule of thumb is, if the outdoor temperatures drop and stay under 65°F (18°C), you might need to winterize your pool.

Take advantage of the warm period to clean, test, and balance the pool water. Do other necessary tweaks that I will discuss later to ensure the water stays clean until you reopen next spring.

How Do You Winterize an Above Ground Pool? Steps to Follow

The winter season is here, and there is nothing you can do to change that. However, if you want to enjoy the refreshing swim again during the hot season, you better winterize your above-ground pool the right way.

Freezing and frigid winter can go hard on any swimming pool; the proper preparations can make reopening superbly easy for you.

I will be discussing with you the steps you need when winterizing your above-ground pool.

Read along!

What Do You Need to Winterize an Above Ground Pool?

Before you can start the winterizing process, ensure you have the following supplies at your disposal:

  • Winterizing chemical kit or the standard Winterizing chemicals
  • Above ground pool skimmer cover
  • Above ground pool winter cover and Cover clips
  • Calcium hardness increaser
  • Alkalinity increaser
  • A pH increaser
  • Pool shock
  • Algaecide Treatment
  • Expansion plugs
  • Return line plugs
  • Cover winch and cable
  • Pool air pillow (a must-have!)
  • Water bags (if you have a walk-around deck)
  • Clarifying enzyme supplement (optional, but recommended)
  • Swimming pool antifreeze (if necessary)

How do you winterize an above ground pool: 10 Steps

These are the steps you need to follow if you need to winterize your above-ground pool right and ideally.

#1. Clean Your Pool

Imagine opening your pool in the spring only to find stains on all the pool surfaces. It can be quite a turnoff. The little prep you undertake here will save you from the potential nasty surprises during the pool reopening.

So, why not clean it before you close it? Cleaning it also eases the whole process of testing and balancing the water chemistry. The cleaning also ensures nothing is left behind to feed any algae and mold that might grow during the closed period.

The first step should be to clean the above-ground pool. Vacuum it entirely, starting with wall brushing, skimming the surfaces, and the filters and pump.

Use the right pool brush depending on the pool wall materials. A wire brush is ideal for the solid, concrete wall but destructive and damaging in vinyl liners.

You might winterize these two components separately later, but this step ensures there is no dirt getting back to the clean pool.

#2. Test Your Pool Water

Open or closed, knowing what’s up with your water chemistry is essential to keeping your pool in tip-top condition. Take a few minutes to test your pool water before you begin closing.

Testing and balancing your pool water doesn’t have to happen only when the swimming pool is operational. It’s crucial to check the water chemistry when closing the pool too.

You only need a few minutes to test it before you can put it to sleep. And you know what, you can do it DIY with test strips or pool water testing kit that you can get in the nearest pool store.

The DIY methods and kits aren’t that accurate. If you need top-most accuracy, you can take your pool water sample to the nearest pool store and ask for the testing service. It might take minutes or an hour, depending on their services.

What you need to check here is if your pool water pH is between 7.4 and 7.6. You’ll also review the alkalinity if it’s between 100 ppm (parts per million) and 150 ppm, with the average 125 ppm being the ideal level.

You will also have to check the pool calcium hardness, which should be between 175 ppm and 225 ppm.

Another thing to test is the chlorine level. The ideal level should be between 1 ppm and 3 ppm.

If your swimming pool uses a different sanitizer, you test its level too to ensure it’s at the ideal level before proceeding.

And since it won’t be possible to adjust the water chemistry during the napping period, it’d be best to keep the water chemistry level high. That way, the water will remain balanced even after the levels decrease over time.

#3. Balance Your Pool Water

If your pool water chemistry is not balanced, here are the few things you need to do to keep it safe during the winter.

#a) Use a Winter Closing Kit

The best and first DIY way of balancing your pool water chemistry is to get an above-ground pool winterizing chemical kit from your nearest local store. It will come with the directions you should follow for perfect use.

#b) Tweak the Water pH

Your pool’s pH level is a measure of how acidic or basic the water is. The lower the level, the more acidic the water is. The higher it is, the more basic the water is.

The pH level readings tell you the acidity or basicity of the pool water. Lower readings show it’s more acidic, and if the readings are on the high side, the water is essential.

As aforementioned in the previous step, the recommended pH level ranges from 7.4 to 7.6, with a higher level being the best during winterization.

If the pool water is more basic, add a pH increaser – it will bring it to the ideal level. If it’s more acidic, you need to add a base – it will help lower it.

#c) Adjust the Water Alkalinity

The pool water alkalinity gives you the measure of hydroxides, carbonates, bicarbonates, and those other alkaline chemicals in the water.

The ideal water alkalinity of your above-ground pool before you close it should range from 100 to 150 ppm, but the more, the better.

There two ways you can adjust the alkalinity in two ways:

  • You can add a base such as sodium bicarbonate or pool alkalinity increaser.
  • Lowering it requires you to add muriatic acid.

You should continuously adjust the alkalinity before the pH. Why? The alkaline substances might initiate a chemical reaction with the sanitizers and affect the pool pH.

#d) Balance the Water Calcium Hardness

Calcium Hardness is the unseen destructive agent that can east away your pool walls, plumbing, or even stain your swimming pool’s excellent look.

The deposits made can settle in your pool or the plumbing, leading to the formation of the tough to clean crusty built.

And you know what, if the water calcium hardness is too low, that is also a problem. The water will draw the calcium from the pool wall or even the plumbing.

The process can cause damages to the tiled pool and metal plumbing. The water will satisfy the calcium hunger by feasting on the grout, plaster, and plumbing leading to metal corroding.

If your above-ground pool doesn’t have any plaster, metal damages might be your biggest concern.

The ideal pool water calcium hardness should be between 175 ppm to 225 ppm.

But if your above-ground pool has plaster or concrete surfaces, you have to keep the calcium levels between 200 ppm to 275 ppm.

If the water calcium hardness is too high, purchase chemicals ideal for lowering it or use freshwater with low calcium hardness to dilute it.

The opposite requires you to add calcium hardness increaser, or you can add calcium chloride. It will even help boost the chlorine levels.

#e) Shock Your Pool

Why should you shock your pool before closing it anyway?

Shocking your pool before you close will help kill bacteria that might be lingering in your pool water. It does also kill the brushed-off and growing algae, mold, and mildew.

If you’re using the regular pool shock, you have to do it few days before closing the pool. If that isn’t possible for you, at least do it the night before the closing day.

You will also need to use a fast-dissolving shock since the typical calcium hypochlorite shock takes 8 to 24 hours to start working.

How do you do it?

You need to add pool shock to power the pool sanitizer during the winter napping period.

It’d be best to consult on the method and direction for your pool shock product. That helps make sure you’re using the ideal amount for the amount of water in the above-ground pool.

#f) Add Algaecide Treatment

Algae always come in surprise. One tiny algae seed could quickly multiply and cause all sorts of issues. Even though it’s optional, you can add it to your swimming pool before closing it. It will help prevent the nasty algae from invading it during the winter period.

It always follows the given directions by the manufacturer for the proper dose. You can use the same amount recommended during regular use.

Another thing you can add to protect your pool from algae growth is clarifying enzyme treatment. The treatment can also help prevent contaminant build-up and liner stains.

It comes in a bottle or convenient tablet or ball you can add to the pool water. It releases payload all winter to keep your pool crystal clear when reopening.

The supplements are the solution if you’ve struggled with a green, murky pool before.

#4. Clear and Store your Pool Lines

Ice never comes easy with pool lines. When the water inside the pipes freezes, it expands, causing damages. That could happen even during mild winters. Cleaning, removing, and storing them make it easier to set it up next spring.

Disconnect the lines, drain all the water, and allow them to air dry. Once dry, store them in a dry play or direct sunlight. Allowing them to dry ensures you don’t get mold and mildew in them during the reopening.

#5. Winterize Your Pool Filter and Pump

The next step is to pack away your pool filter and pump to protect it from weather elements, ice, and snow.

Winterizing the Pump

Since you removed the pool lines earlier, it’s relatively easy to disconnect the pump. All you need is to remove all the drain plugs connected to and from the pump and then disconnect the pool pump.

If you’re using a chlorinator, you will have to remove it and all the hoses connecting it. Ensure everything is dry and take all the drain plugs, and place them in the pump basket for safe storage. You have to keep the chlorinator and the hoses indoors in a cool, dry place to extend their lifetime.

Winterize the Filter

The best method to winterize an above-ground pool filter depends on the type installed.

Sand Filter

Sand filters come with a pre-determined method of how you can winterize them. All you need is to set your pool filter multiport valve to the Winterize position and open the drain plug to allow all the water inside it to drain completely.

If there are a bleeder valve and sight glass on the filter multiport valve, keep them safe in a safe sport for easy retrieval next season.

You can take the filter indoors, but you can leave it there if the weight is too heavy. If you do so, open all the drain plugs. That way, even if the water in it condenses and freezes, it won’t crack it.

Cartridge Filter

Unlike sand filter, with a cartridge filter, you’ve to get dirty. Please take out the cartridge and drain it. Rinse it with a hose, return it and keep the valves wide open. Take it indoors for safe storage.

Diatomaceous Earth (D.E.) Cartridge Filter

Here it would be best if you drained the grids or fingers depending on what your D.E filter has. Use a hose to remove all the D.E and leave the filter valves open.

#6. Winterize saltwater system

If your above-ground pool uses a saltwater system, you will need to winterize or remove it before the winter comes.

You can do it by switching the chlorine generator to a winter setting, if there is one. If it doesn’t have it, it’d be best to remove the whole salt system or the electrolytic cell, clean it and store it indoors during the winter.

Keeping it clean helps extend its life and reduce hardware problems during the pool reopening. Remember you will need to put it together.

#7. Winterizing the Pool Skimmer

Another thing you need to winterize is the skimmer. You could decide to remove the skimmer basket entirely and store it in a safer, dry place during the winter period.

You could also decide to keep it on, but you’ll have to cover it. The cover protects the entire skimmer by sealing it from elements.

If you decide to leave the skimmer on and covering it, you won’t have to lower the pool water level below it, which will save time and hassle.

But if you choose not to cover your pool skimmer, you’ve to keep an eye on it during this period and make sure it drains well when it rains.

Keep its bottom free and clear. Also, don’t plug it in during the winter.

Remember, if water were to accumulate in the skimmer during the winter and freeze, it would expand and crack it.

Another thing, when the snow or ice load gets too heavy, it can also compromise your skimmer walls.

#8. Winterize the Pool Accessories

It’s always best not to overlook the pool accessories like toys, ladder, and more that you may have during the pool closing.

If you leave them, the freezing could damage them and your pool. At times they could freeze and puncture the lining or even get eaten away by rust and corrosion.

Another thing, corroding metal can easily contaminate the pool water or even cause costly hardware issues.

So, you ought to pick up all the pool accessories you have, clean them with an ideal multi-purpose surface cleaner and leave them to dry. Once dry, please pick them up and take them indoors for storage in a clean, dry room.

#9. Install the Pool Pillow

When you install a pool cover, the cover will sag toward the inside, especially during the winters. All the ice, snow, and rainwater will use it as the resting place.

A pool pillow works as an ice compensator. It compensates for the ice and snow pressure resting on the cover.

It needs to be placed under the cover to protect the cover sides and pool walls from tearing apart.

And note this, it’d be best to inflate the pool pillow about 50% of its capacity. That way, it can compress without popping out immediately after the first snowfall.

Blow the air in and tie all the edges with a thin rope. The tying will help hold the pillow in the middle. You can also use a centering accessory designed to keep the gadget in the center automatically.

Your pool pillow might also have built-in grommets for allowing you to secure it safely at the pool center. It’s not a must to center it, but it does protect the pool cover and walls.

You can also use duct tape to seal the seam and valves. It reduces air loss and leaks, thus extending its life.

#10. Install the Pool Cover

It’s time to close the pool now. The last steps involve installing your pool cover and secure it. Use cable and winch for the job. You could also combine the winter cover clips and cable for a secure hold.

When you combine the clips and cable, you will be ensuring you give your pool cover a snug fit and gift yourself with some peace of mind. You could also add bags of water for a more secure fit.

Refrain from using stones, bricks, and anything that can damage your pool liner if they were to find their way into your pool.

Take some time during the winter to inspect the cover and ensure it stays dry. You can get a pool cover pump. It will help you remove the water resting on the cover to keep it in good shape.


Congratulations! You just completed winterizing your above-ground swimming pool. Now you can enjoy the cold season the way you love with some peace of mind. It’s always crucial to keep an eye on the pool to ensure things are going well. If you notice something wrong, you can call pool experts to deal with it before it can become unsalvageable. But if you winterize the swimming pool right, you don’t have to worry much. Inspection is just a precaution.

About the author

Sharif Miah

Hi! I'm Sharif, the founder of Globo Pool® and I have been working in the pool & hot tub industry for the last few years. I love to share my experiences with people & hope you are enjoying my information and lessons!

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