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How to Close An Above Ground Pool in 6 Steps

Labor Day has passed and for pool owners that means closing down the pool for the fall and winter seasons.

As depressing as it may be, it doesn’t have to be hard and take an entire Saturday or Sunday to do. With a little help and the proper know-how, you can successfully close down your above ground swimming pool in a matter of hours, no matter if it’s for the season, or for pool remodeling.

How to Close An Above Ground Pool in 6 Steps

What You’ll Need:

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1. Test and Clean The Water

Before you begin closing your pool, get the water tested – at your local pool store or using your own test strips – to make sure the pool is properly balanced.

You want to make sure that your pool’s pH is between 7.4 and 7.6, and the alkalinity is between 100 and 150ppm. It’s better to be on the high side of these ranges when closing the pool.

Also, before you start adding any winter chemicals, be sure your pool is as clean as possible. That mean, vacuuming the entire pool, brushing down the walls, and skimming the surface.

2. Add The Winter Chemicals

1. Make Sure the pH is Perfect

The pH level is the measure of how acidic or basic the water in your pool is. Ideally, you are shooting for your water’s pH level to be somewhere between 7.2 to 7.8.

The lower the level, the more acidic the water is. The higher it is, the more basic the water is. If your water is acidic, you will need to add a base to lower the acidity, if it is too basic, you will need to add acid to the water to bring it into proper balance.

2. Add Some Alkalinity

Alkalinity is the measure of carbonates, bicarbonates, hydroxides and other alkaline substances in the water and is strongly related to your pH levels. Ideally, you are looking for an alkalinity of 80 – 120 ppm.

Much like pH, to raise your alkalinity you need to add a base such as sodium bicarbonate to the water. To lower the alkalinity, you must add acid.

3. Hone in On Calcium Hardness

How hard is your water? When your water is considered hard, it will deposit calcium in your pool and the plumbing leading to a buildup over time. Of course, if your water is too soft, it will try to draw the calcium it needs from inside the pool damaging it in the process.

Your water will always try to balance itself, but if you help it along you can save your pool a lot of problems in the future. If the water is too hard, you can purchase chemicals to lower the hardness or simply dilute it with fresh water that isn’t hard. If it is too soft, you must add calcium chloride to bring the levels into balance.

4. Shock The Pool Before You Close

If you don’t have a kit, shock the pool with chlorine shock and add the recommended amount of winter algaecide based on the back of the bottle for your size pool.

Since you are closing the pool, you can use a 15-minute fast-dissolving shock before you put the cover on instead of using a typical calcium hypochlorite shock that will take 8 hours. If you decide to use standard shock, just make sure you add it to the pool the night before you want to close it.

5. What About Some Winter Algaecide?

While it’s completely optional, you can add a polyquat Algaecide to your pool just before closing it. Follow the directions on the back of the bottle for the proper dose. You’ll want to add the same dose they recommend for starting up the swimming pool.

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Using a Winter Closing Kit For Ease

If you have a winter chemical kit, just add everything based on the directions.

NOTE: Some winter chemical kits don’t require you to run the filter when adding them. Make sure you check the directions to see which type of kit you have. If your kit doesn’t require your filter and pump to be running, you can save this step right before you put the cover on.


BONUS: I recommended using a WinterPill earlier. While this is not absolutely necessary, it adds a little bit of insurance. This product will help ensure you open up to a clear pool in the spring. Plus, it’s easy to use: just pop a hole in it and toss it in the water — you’re done.

3. Plug It Up

aquadoorRemove the eyeball fitting on your return line and plug it up with a rubber plug with a wingnut.

On the skimmer, remove the basket (store away for the winter). If you want, you can use a winter skimmer cover. Winter skimmer covers are plates that cover the entire skimmer. By using one of these, you won’t have to drain the pool below the skimmer, which can come in handy.

If you don’t want to use one of these, just make sure the skimmer can drain out water if it rains. Do not plug up the bottom of the skimmer.

NOTE: If water fills up in your empty skimmer over the winter and then freezes, it can cause your skimmer to crack. Also, if snow or an obscene amount of water fills up, the weight could be bad for you skimmer wall.

4. Winterize The Filter and Pump

The Pump

Completely remove all drain plugs to drain and remove the pump, chlorinator (if you have one), and all the hoses. Store all the drain plugs (including the ones from the filter) in the pump basket so that you keep them all together and you wont loose them. Keep the pump, chlorinator and hoses indoors to prolong their lives.

The Filter

If you have a sand filter, set your multiport valve to Winterize and remove the drain plug at the bottom, letting the filter completely drain out. If your multiport valve has a bleeder valve and at a sight glass, remove those too and store them in the pump basket.

If you have a D.E. filter, drain it, rinse off the grids (or fingers) with a hose to get all the excess D.E. off, and leave the valves open.

If you have a cartridge filter, drain it, rinse off the cartridge with a hose, store the cartridge indoors for the winter, and leave the valves open.


After you’ve disconnected your filter and pump system, you should store all your equipment indoors. This includes your filter, pump, chlorinator, heater, and any other equipment you might have. If you have a sand filter, this can be a difficult piece to move indoors because of the weight of the sand. If you want to leave it outside, just make sure all the drain plugs are removed. That way, if water or condensation builds up inside the tank and freezes, it won’t crack the filter tank.

Other filters, such as D.E. and cartridge, should be light enough to store indoors.

5. Drain It And Add The Air Pillow

The “lowering the water level” debate is all about freezing and cracking of the skimmer.

Make sure you remove the hose from your skimmer so it can drain properly and install a winter skimmer cover plate.

If you do these things, you don’t have to drain your pool. Keeping the water level normal will be better for your winter cover.

NOTE: If you have a solid cover, draining the water below the return lines may put added pressure on your cover when rain water and snow collect on top. You’ll need to keep draining water off the cover with a winter cover pump or siphon to protect it.

Blow up the air pillow and place it in the middle of the pool. You can use a thin rope to secure it to either side of the pool so that it stays in the middle, or look at getting a Pool Pillow Pal.

NOTE: It honestly doesn’t matter if the pillow stays in the middle of your pool all winter because the reason above ground pool owners use an air pillow is to prevent the sides from bearing the pressure when the water turns to ice and expands. It’s not needed but it’s highly recommended!

This is also a good time to remove the ladder or any other equipment you have in the pool.

6. Put The Cover On

OLYMPUS DIGITAL CAMERAPlace your pool cover over top of your pool –  and over the air pillow – and secure it by using the cable and winch, water bags, or a combination of winter cover clips and a cable.

I recommend using a combination of winter cover clips and a cable and winch. If you have a walk around deck. I recommend also using water bags (not bricks or anything that could damage your liner if it fell into the pool).

Make sure that throughout the winter you keep an eye on your cover and try to keep the cover relatively dry. We recommend buying a small sump pump in order to keep good care of your winter cover.

Get More Information on Closing Your Above Ground Pool

Are you on Pinterest? I created a board containing all of the best pool care articles from Swim University and around the web. You should totally follow the board below. Also, feel free to ask questions in the comment section below.

Follow Swim University’s board Swimming Pool Care on Pinterest.

Happy Swimming! Happy Closing!

How to Close An Above Ground Pool in 6 Steps

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Last Updated: Sunday, July 28th, 2013