How to Close Your Inground Pool for the Season—The Right Way

Well, all good things must come to an end. I mean, no weekend or vacation lasts forever. Even what might feel like an endless summer is never actually endless. And unless you live in a place without seasons, where you might be able to expect a comfortable swim on New Year’s Day—which, by the way, means you have my envy—you’ll need to close for pool for the harsh, cold, swim-free months. I’ll explain why you should close your pool, when to do it, what you’ll need, and finally, how to close your pool the right way. Get ready to make pool season next year is all the easier to dive into, and save yourself some serious time and money, too.

Why Should You Close Your Pool for the Winter?

Not only should you close your pool, but you should do it right—the last thing you want on the first day of swim season is to open your pool cover to a disgusting, cloudy combination of debris, algae, grime, even white mold. Not to mention that if cloudy water reaches that level of gross, you can bet your greater system, especially your skimmer, has taken a hit. If you close your pool the right way now, it’ll take even less effort (and money) to open it up again in the spring.

But closing your pool isn’t just to help you out next year—it’s also to help you now. If you close your pool, you won’t need to keep cleaning out debris and adding chemicals, which takes time, and running your pool pump and greater circulation system, which costs big time. If you’re not swimming, that’s a lot of time and effort that just isn’t necessary—even if you do have a seriously cost-saving variable speed pump

When Closing Your Pool, Timing is Key 

This one is a win-win, and you’ll be surprised you didn’t think of it yourself. My advice? If your temperatures typically stay below 65 degrees, leave your pool open until the weather cools down below that point. That way, you can treat and use your pool as usual right up until it’s time to say goodbye for a few months—and it’ll help keep your pool algae-free through the winter. 

If during the winter you have a few warm days above 65 degrees, you can treat your water on those warm days to prevent algae and give yourself a leg up for when you open your pool next season. Hey, the work you’d otherwise have to do later would far outweigh the work you’re doing now.

how to close your inground pool

Get the Gear 

You’re definitely going to want to be prepared for this. Thankfully, you probably have most of this gear already on hand. And don’t worry—whatever stock up on this year, you’ll be able to use next year. Here’s what you’ll need: 

- Winter pool cover

- Pool brush

- Pool vacuum or robotic cleaner

- Winter pool plugs for return jets

- Skimmer plug

- Shop-Vac or air compressor

- WinterPill

- Tools for removing pool accessories, like ladders

- Winter pool cover pump

Get the Chemicals

Okay, if you don’t have any of these—with the exception of a metal sequestrant unless you have metal stains, and cyanuric acid unless you have unstabilized chlorine, and antifreeze or pool enzymes, which are just plain optional—it’s time to update your inventory. Here’s the full list. 

- Water test strips

- Chlorine or your choice of sanitizer

- pH increaser

- pH decreaser

- Alkalinity increaser

- Calcium hardness increaser

- Algaecide

- Pool shock

- Metal sequestrant

- Cyanuric acid

- Antifreeze for Pools

- Pool Enzymes 

How to Close Your Pool for the Season—In Ten Steps 

Now that you’re geared up, it’s time to get working. I won’t pretend that it’s easy to close your pool for the summer, but I can tell you that it’ll all be worth it in the spring. And once you’ve got this straightforward process down, it’ll come back to you faster and faster every year. Because as you know: when it comes to pool maintenance, you’re in this for the long haul. Better eat some protein for this first step.

Step 1: Use Some Elbow Grease to Clean Your Pool

Use a brush to scrape down the bottom and sides of your pool, especially trouble spots that are especially susceptible to algae. This will both dislodge any microscopic algae spores that might bloom later if left alone, and will help your pool shock work extra hard in a few steps. My top recommended brush is the only one like it on the market, thanks to a patented 360 degree brush head perfect for getting trouble spots. Plus, it was developed by longtime pool servicers who were tired of aches and pains that resulted from brushing stairs and other corners.

Also, don’t forget to vacuum your pool floor with a trustworthy and heavy-duty model like the Blue Torrent MyBot Robotic Cleaner to pick up any sediment that might’ve settled. Do this after you brush your pool, so all that sediment you broke off from your pools and walls doesn’t take advantage of the winter months to cling on again.

Step 2: Put Your Water to the Test

You might think that since you’re closing your pool, your water no longer needs to be balanced. But hey, remember this: while your pool is closed, it’ll be covered and largely safe from the elements. Plus, you won’t be running your pump eight hours a day. So what you do now will give your water a serious leg up throughout the winter, and is sure to last longer than your typical application.

If your sanitizer and other chemicals are properly balanced, your pool is all the more protected from corrosion, extreme clouding up, and becoming an overall murky mess that will cost big to fix. Sound good to you? Get ready to get even more excited with this next step.

how to close your inground pool

Step 3: Wave Summer Goodbye by Adding Winterizing Chemicals

Sure, balancing your chemicals before closing will sure help the water from becoming an actual swamp. But this isn’t any regular weekly maintenance, at least not for now. If your pool is at risk for algae, add one or two doses of algaecide. If you do double-dose on algae (since remember, it usually contains copper) or if you have high levels of metals in your water, go ahead and add a dose of metal sequestrant. This will help the metals from attaching to your pool walls or floors in the form of ugly stains.

There are also some chemicals that could give your pool an extra boost, even if it doesn’t typically run into the problems above. Pool enzymes can be added to your water to help algaecide attack organic contaminants. There’s also a great chlorine and clarifier combination called the WinterPill, which dissolves over several months’ time. And if you live in a place that gets cold enough for your pipes to freeze, use a pool-grade antifreeze—not the toxic kind designed for cars.

Step 4: Shock Your Pool—So There’s No Cause for Alarm Later

Ah, a break—but only if you have an outdoor pool. It’s time to shock your pool, but remember that you’ll need to do this at dusk or at night or the sun will burn it off before it has the chance to work. So shock your pool after sunset tonight, run your pool pump for eight hours, and get ready to do these next steps tomorrow.

If you currently have algae blooms that you’ve just brushed and vacuumed up, you can double or triple the amount of shock you use depending on the algae’s color. But no matter what, be sure you’re measuring out the right amount of shock for your pool size.

Step 5: Drain Part of Your Pool—Or Don’t

This one’s only for those of us who have to worry about freezing pipes in the winter. Lowering your water level will help big time to prevent freezing damage, and all it takes is pumping your water to “waste” until the water line is where you want to be. Be sure to check with your local authorities about where that water should go—especially since it’s just been chemically treated. The last thing you want is fees and environmental damage on your hands.

So how low should your water line go from its usual position of halfway up the skimmer? Well, not too low at all, since that winter pool cover needs water to hold it up, especially after it gets covered with debris or heavy snow. It also depends on your liner, and usually the manufacturers will have opinions. Unless yours says differently, lower your water one inch for a vinyl liner. For a plaster or non-vinyl liner, lower it six inches for a solid pool cover, eighteen to twenty-four inches for a mesh cover, and to the bottom of the skimmer if you have an automatic pool cover.

Step 6: Give Your Filter Pump a Leg Up

Your filter is a holding place for all the gunk that it can pick up from your water as it circulates through. The last thing you want is to rev your filter up on the first pool day of next year and have your water coming into contact with contaminants that have been festering all winter. Start off fresh by cleaning your filter—or replacing the media entirely.

For cartridge filters, no backwashing is necessary (or possible!). Just take the cartridge out, submerge it in water with pool filter cleaner, rinse it out, let it dry, and replace it.

For sand and diatomaceous earth (DE) filters it’s high time for a backwash. Be sure to switch your valve back over to “filter,” and drain all water out of the pump and filter (and pool heater, if you’re one of those lucky enough to have one).

how to close an inground pool

Step 7: Get That Water Out of Your System

I don’t just mean getting used to the idea that swimming isn’t going to happen for a few months—but that, too. This is another one for those of us who have to worry about freezing pipes in the winter. Antifreeze will certainly help, but it won’t do all the work.

In order to prevent your pipes from freezing—and then cracking—you want to purge your plumbing of every drop of water that could respond to the cold temperatures. Using an air compressor or a ShopVac, you’ll need to blow air through the lines to make sure they’re dry. Since this step is a fine balance of both important and difficult, it’s totally okay to hire a professional. But if you’re set on keeping it DIY, here’s how to get it done in ten steps:

How to Blow Out Your Plumbing Lines

1.     Remove all skimmer baskets and return fittings, which look like giant screws around the diameter of your pipes.

2.     Remove all the drain plugs from your filter system.

3.     Set your multiport valve to “recirculate.”

4.     Attach your ShopVac or air compressor (and an adapter, if needed) to the pump’s drain plug opening and blow air through the system.

5.     Watch for bubbles to come out of the system via the return lines and skimmer.

6.     Use your ShopVac to remove water from the skimmer until it’s dry.

7.     Insert a skimmer plug into the hole at the bottom of the skimmer.

8.     Insert winter pool plugs in the return lines as you see air bubbles coming out of each one.

9.     Turn the valve in front of your pump to the main drain setting to move air toward the main rain, and watch the deep end of your pool for bubbles. Let it run for about a minute.

10.  Turn your pump valve back to the skimmer line, shut off your air compressor, and put a valve in your pump to prevent leaking. You’re done!

Step 8: Take Those Accessories (And More) Down

To make sure your pool is completely covered from debris and prevent unnecessary corrosion, you definitely want to remove any pool ladders, rails, and other accessories you have installed in your pool. This is also a great opportunity to give them a good rub down, then let them dry and store them in a safe spot until next pool season. Make sure all electronics are stored indoors for the season.

If you live in a warm climate and didn’t need to blow out your lines, you’ll still need to remove the remove return fittings from your jets and the line for your automatic cleaner (if you don’t have a super easy plug-in model like the BlueTorrent Stinger Automatic Cleaner), which look like giant screws around the diameter of your pipes. Next, clean out your skimmer baskets, which you can go ahead and remove.

Do you have a saltwater pool? Now is the time to remove your salt water chlorine generator, drain it, and store it. Plus, you can turn off all power and gas to your system. You won’t be needing them—and you’re about to love the bills that come in.

Step 9: Install a Winter Cover

Next, it’s time to put your winter cover on. This will keep your pool water safe from debris and contaminants, and keep the chemicals in your water without getting seriously diluted by rain, snow, or whatever else might come your pool’s way. Most covers can even make sure all gaps are gone, so no worries about skimming out leaves—though you will want to check on the cover periodically.

Winter covers usually use tubes or weights to keep it from sinking further into the pool over time, though they do tend to rest of the water in your pool. Once it rains, you’ll also find that the center of the cover will eventually have a big puddle of water. This is normal, but don’t intervene and it will eventually get so heavy that it sinks into your pool—bringing all that nasty water and debris in, which undermines a lot of the work we just did to keep the first day of next year’s pool season as happy as it should be. My recommendation is a durable and heavy-duty cover pump like the Black & Decker 1500 GPH Automatic Pool Cover Pump. As one owner noted, it “saves so much time.” That’s what I’m talking about.

how to close your inground pool

Step 10: Look Forward to Next Year! 

Well, that’s it folks. Another great season has come to a close: our bathing suits are going back to the back of the closet, our floaties are properly deflated, and now we have something to look forward to. Since you took the time to close your pool the right way, the first day of next year’s pool season is going to be a breeze. Until then, it’s all about colorful leaves and hot drinks—and very light pool maintenance. Enjoy.


Related articles:

Sand in Your Pool? Here’s Why—And How to Fix It

Chlorinate Your Pool in Three Easy Steps

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