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How to Close An Inground Pool in 6 Steps

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Unfortunately, it’s that time of year again to break out the winter cover and close up the pool. You can successfully learn how to close an inground pool in just a day without paying anyone.

What You Need:

1. Remove Deck and Skimmer Equipment

Remove your diving board, ladders, rails, safety ropes, and any other equipment you might have in and around the pool (not your filter system).

Then, remove the eyeball fittings from all your return lines and the skimmer baskets from your skimmers.

NOTE: If you have a dedicated line for an automatic cleaner, remove the plastic adapter. All return lines should be large, threaded openings that will all fit the same sized rubber plug with a wing-nut.

2. Test and Clean The Pool Water

Test you pool water to make sure it’s properly balanced. I suggest taking a sample of water to your local pool dealer to get it thoroughly checked.

You can also use test strips to make sure the pH is between 7.4 and 7.6 and your alkalinity is between 100ppm and 150ppm. Your chlorine level is between 1 and 3 parts per million. If you don’t use chlorine, make sure your sanitizer is at the proper level.

A properly balanced pool will protect you from corrosion and scale build-up that can occur while it’s closed.

NOTE: Your chemical ranges can be on the high-side when closing your pool because chances are they will drop during the winter.

Before adding the winter chemicals, you want to make sure your pool is super clean. That means, vacuuming the floor of your pool with an automatic cleaner or manually, brushing down the walls and steps, and skimming the surface of the water.

3. Add The Winter Chemicals

Once your pool is balanced and cleaned, you can add the winterizing chemicals. You’ll need:

NOTE: If you buy a chemical kit, some will not require you to run your pump and filter while adding the chemicals. If this is the case, you can save this step till right before you put the cover on. Otherwise, now is the time to add the chemicals while your filter and pump is still operational.

I like the idea of buying a pool closing kit. While you might not NEED everything in the kit, it makes the job of adding chemicals for pool closing very simple — and I like simple. The less time I have to think and add pool chemicals, the better.

If you want to keep things super simple for yourself and don’t mind spending the extra cash, then I suggest getting a kit. Here’s a link to one I like:

Check the directions on your winter chemicals or kit before proceeding.

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.

Shock Your Pool The Night Before You Close

In other words, add a large dose of sanitizer to bring the levels up. This will make sure no algae occurs and give you pool once last snazzier shock.

NOTE: the later you close and the earlier you open your pool will help you battle algae, which doesn’t grow at water temperatures below 60 degrees.

4. Backwash and Clean The Filter And Pump


Once the filter is backwashed, you can open up your pump lid and remove any debris that is in the basket. Make sure to put the basket back in when you’re done and put the lid back on.

Also, make sure you turn your filter back to “Filter” on your multi-port valve before blowing out the lines.

At this time, if you are not using a winter skimmer plate, you should drain the pool 6 inches below the skimmer.

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

If you have an inground pool, you must blow out the pipes. If you don’t want to do it yourself, hire a professional to do it for you. Make sure you property plug the return jets and install a Gizzmo in your skimmer to protect it from cracking.

If you do these things, you don’t have to drain your pool. However, If you have a tile border in your pool, you should drain it at least 4″ below the tile to protect it.

Keeping the water level normal will be better for your winter cover.

5. Blow Out The Lines

NOTE: If you are unsure how to do this properly after reading this section, hire a reputable company to come and blow your lines out for you. If you do not do this step correctly, you run the risk of your pipes cracking underground. This can be very expensive to fix, come spring. Also, if you do not have a good air compressor, buy one or hire someone to do this for you.

How to Blow Out Your Pool Lines

Start by making sure your valves are turned so that the skimmers and the main drain are open. If you don’t have a main drain at the bottom of your pool, then you will only be dealing with one opening.

Hook up the air compressor to your pump by unscrewing the drain plug that’s on the pump housing (the part with the lid) and thread your air compressor into the drain plug opening. You may need to purchase an adapter for your air compressor if you don’t have the proper threading.

Start blowing air into the lines until you see bubbles coming from the return lines and the skimmers. Let it run for about 2 minutes.

Look for whichever line is blowing first, you’ll see bubbles coming from the return lines or the skimmers. We’ll assume that the bubbles are coming from the skimmer first.

gizmoTake your gizmo or rubber plug and plug up the hole in the bottom of the skimmer where the air is coming from. If you’re using a gizmo, just thread the gizmo in the hole. A gizmo is a long hollow, plastic tube that threads into the skimmer opening and prevents your skimmer from cracking in the winter. The gizmo is an ice compensator, so if water gets into your skimmer and freezes during the winter, when the ice expands, the gizmo will absorb the expansion rather than your skimmer, which protects your skimmer from cracking. If you don’t have a gizmo, and you are just using a rubber plug, make sure you throw in a plastic soda bottle (with the cap on) to act as your ice compensator. Do this in all your skimmers.

Next, walk around your pool and plug up all the return lines (the ones that are blowing air bubbles) with rubber plugs nice and tight. You don’t want to see any more bubbles coming out when you put the plugs in. The main drain will be the last to blow, but you don’t have to swim to the bottom and plug it up.

Turn off the air compressor.

Lastly, if you have a heater, you are going to need to blow the water out of it. Again, if you are unsure of how to do this, please hire a professional.

Remove the drain plugs from the heater and turn the air compressor back on. You now what to direct all the air into your heater, so close off all the valves except the one to the heater. You should start to see water coming out of the heater drains. Keep the air compressor running until you see no more water.

Replace the drain plugs on your heater and remove the drain plugs from the filter and chlorinator if you have one.

Turn off the air compressor and remove it from the pump. Store all the drain plugs in the pump housing for safe keeping.

Do I Need to Put Antifreeze In My Pool When I Close It?

In some parts of the world, it’s important to close and winterize your inground swimming pool, which includes blowing out all the lines so that the water won’t freeze and crack the pipes underground during the cold winter months — which can be an extremely expensive fix.

Swimming Pool Antifreeze is a chemical you can add to the water in your pipes to keep the water from freezing and cracking them during the winter. However, if the pool was properly winterized and the pipes we completely blown out, there should be no water in the pipes to freeze. Therefore, you do not need to add antifreeze if the pipes have been blown out.

I highly recommend that you close your inground properly, which includes having the lines blown out. I would avoid using antifreeze at all costs. Adding more chemicals to your pool than what is needed is never my recommendation.

NOTE: You might find information from other sources that will suggest adding antifreeze as a backup in case the lines weren’t blown out properly. If this is something you want to do, because you don’t feel confident in the job, then go for it. Pool antifreeze is made to be safe for your water when it enters back in during the spring.

What If I Don’t Blow Out The Pool Lines?

If you’re on a budget when it’s time to close a pool, and don’t want the hassle of either hiring a professional to blow out the lines or doing it yourself, then adding antifreeze is your only other option from keeping your pipes from cracking during the winter.

NOTE: Do NOT use car antifreeze!!! Instead, you can buy pool antifreeze here.

Camco ISwimming Pool Anti-Freeze - 1 qt

Camco ISwimming Pool Anti-Freeze - 1 qt

List Price:  $19.70
Price:  $11.48
You Save:  $8.22 (42%)

Buy Now On Amazon

If this is the option you have to go with, here are a few steps to walk you through it:

  1. Remove the baskets from your skimmer(s). If there’s a plug already in it, remove it so you can add the antifreeze.
  2. Make sure the water level of your pool is drained below the skimmer.
  3. Add the antifreeze into the open hole in your skimmer(s). Use the chart below to determine how much you’ll need to add.

Pool Antifreeze Chart

6. Put The Winter Cover On

Place the cover over your pool. If you use a safety cover, consult your manual on how to put this on.

If you are using a simple plastic cover, just make sure there are no rips or tears. If there are, you can patch them by placing duct tape on both sides of the cover. Use water tubes to secure then make sure when filling the water tubes make sure you only fill them about 85 percent of the way to allow for expansion when they freeze. Make sure the tubes are not leaking before putting them on.

NOTE: It is not recommended to use anything but water tubes to secure your plastic covers. Water tubes, if they happen to fall in your pool, will not cause any damage to your liner or concrete much like a brick or cinder blocks will.

Happy Swimming! Good Luck Closing!

Recommended Reading

Pool Safety Covers: How to Choose the Right One
Mesh or solid? Or maybe the new kid in town: hybrid? Which pool safety cover is right for you and your pool? Find out before you make that investment.
How to Use a Pool Air Pillow With Your Winter Cover
The purpose of a pool air pillow is to protect your pool from potential rain, snow, and ice damage over the winter. Learn how to install a pool air pillow.
How to Close An Above Ground Pool in 6 Steps
Want to learn how to close an above ground pool? You're in luck! I've put together this easy-to-follow guide that will help you get it done in ONLY 6 steps.
17 Pool Closing Tips From Industry Professionals
We asked swimming pool industry experts to share their best pool closing tips for the winter and we've got some really good ones you should follow.

The Art of Pool Care

Frustrated by adding chemicals and trying to keep your pool clear all the time?

We cut out all the fluff and confusion of pool maintenance and stripped it down to the bare bones in this easy-to-read illustrated digital guide.

Click here to learn more

Last Updated: Sunday, July 28th, 2013