How To Winterize Your Swimming Pool


  3.75 out of 5 stars on 4 ratings
(Click on a star to add your rating)

By winterizing your swimming pool properly, you spend less time and money when you open your swimming pool in the spring, eliminate additional electrical costs, chemicals and cleaning. You also avoid possible freeze damage to the equipment and plumbing.

Step by Step


Step 1

Water testing- The first step in winterizing your swimming pool is to test your pool chemicals. Several days prior to closing the pool, test the water for pH, total alkalinity, calcium hardness and chlorine. Adjust the levels if necessary. It is important to get the water balanced to protect the pool from corrosion or scale buildup that can occur during the winter.

CLICK HERE FOR PART 3 How To Maintain A Swimming Pool Part 3 (Adjusting Chemicals)

Step 2

Clean your Pool- The next step in winterizing is to clean your swimming pool. Cleaning your swimming pool is an important step in swimming pool winterizing. Remove any large debris using a leaf rake. Brush and vacuum the sides and bottom of the swimming pool. Use a clarifier or flocculant to get the water crystal clear. Lower water level while vacuuming (set filter to waste if applicable). Clean the tile line with a tile & vinyl cleaner to remove the scum line. This will be easier to do now before it sets during the winter months.

Step 3

Winterizing kit- To help protect the water during the winter months, use a swimming pool winterizing kit. Additional algaecide and shock can be purchased separately for larger size pools.

Step 4

Clean the filter, pump, and skimmer- Remove any debris and clean the skimmer basket. Remove any other floating debris left in the skimmer before replacing the basket. Remove any unused chlorine from the chlorinator. Cartridges and D.E. grids should be cleaned thoroughly and rinsed clean with a garden hose. If you own a sand filter, set your filter valve to backwash. Your sand filter should be backwashed to get all remaining dirt and grime out of the filter. Your filter should take about 2-5 minutes to clean. You will be able to see the water get clean using the filter's sight glass. Once the filter has been cleaned, you can clean out the pool pump. With your pump shut off, remove the pump lid and pull out any leaves and large debris from the pump basket.

Step 5

Lower water level/Blow out lines- Lower the water of the swimming pool below the skimmer. Using an air compressor or blower side of a shop vac, blow water out of swimming pool plumbing by blowing air down the skimmer and through the plumbing. You can connect the air compressor to your pump by unscrewing the drain plug on the pump. Once you see air bubbles come out of the returns, you can use either an expandable or threaded plug to close the return openings. The swimming pool heater and other equipment will also need to have the water removed from them in the same fashion.

Step 6

Anti-freeze (for hard pvc plumbing)- Add Anti-Freeze to plumbing and install threaded winter plugs to return fittings to keep water out of lines. You can also add a Skimmer Guard to your pool skimmer. Anti-Freeze is a non-toxic formula. DO NOT USE AUTOMOBILE ANTIFREEZE. For an above ground swimming pool, you would simply remove the flexible hoses connected to the pump, filter and pool.

Step 7

Remove drain plugs- Remove all drain plugs from the pump, filter tank and any other pool equipment. Follow the manufacturers instructions for your specific equipment. Place all drain plugs in pump basket for storage. If you are in heavy winter conditions you may want to consider detaching the filter and pump and storing them indoors for the winter.

Step 8

Winter cover- The next step is to add the winter cover. For an above ground pool, use an air pillow underneath the cover. Air pillows will "tent" the cover and direct water toward the edge of pool for easier removal. They will also allow forming ice to crack inward preventing damage to the shell or structure of the pool. Place the winter cover over pool surface, black side down. Secure it in place using a cable and winch. For in-ground pools or pools with surrounding decks, you can use water tubes to secure the cover in place. You can use either a double or single winter tubes. Double tubes are a little more reliable so if one side of the tube get punctured the other side will still hold the cover in place until you get a chance to replace it. Using a garden hose fill the tubes with water and close the lid. Corner water tubes are also available for the corners of your swimming pool. If you have a safety cover or plan on using a safety cover, the cover is held in place with anchors.

Step 9

Additional equipment- Cover any equipment (diving board, ladders etc..) that can't be removed and stored indoors. Refer to the manufacturer's recommendations for winterizing.


(1 to 10 of 10)

 Posted: 11/16/2019 

I have a 22k gal in ground pool. There is a working 'Thermotrol' small unit attached. I am told if the air goes below 35 degrees then it auto turns on the system. Bypasses heater. Is there any closing processes I need to do? Thank-You from Ray

InyoPools Product Specialist  Posted: 11/19/2019 

That feature is called a freeze protect; it kicks on when there is a danger of water freezing in the pipes, causing them to burst. It is not necessary to winterize the pool unless you experience subzero temps regularly that may be able to freeze moving water in the pipes.

 Posted: 11/5/2019 

Hayward pool pump. Do I NEED to disconnect and take motor indoors for a northeastern winter?

InyoPools Product Specialist  Posted: 11/5/2019 

If there is a chance that snow could cover it or snowmelt can damage the motor, then it would be best to remove the motor.

 Posted: 9/21/2018 

Hello Matt - Before adding any of the chemicals in the kit, we recommend balancing the water. This would include the following parameters: pH 7.2-7.6, Alkalinity 80-120 ppm, Calcium Hardness 175-220 ppm. Once you achieve those ranges, add the shock that is included with the kit. Wait 24-48 hours and then add the other two chemicals. They can be added one after the other in no particular order. Let the water circulate for 1-2 hours and then proceed with the closing.

 Posted: 9/21/2018 

Hi, I ordered and have received the 30k gallon pool closing kit. But it came without any instructions. What order should I put in the chemicals and how long should it circulate before continuing? Thanks!

InyoPools Product Specialist  Posted: 9/17/2017 

Keeran1 - I haven't seen the 65-degree reference, but I would guess that this is a somewhat arbitrary point in the season where you would either stop using the pool or want to start using it again.

 Posted: 9/15/2017 

I was wondering, I had read somewhere that you need to have the water temp go below a certain temp before closing the pool or rather using the winterizing chemicals and turning off the pump for the season so as to not get a lot of algae etc just as one should start up the pool in the spring once the water reaches 65 degrees. Does this hold true? Is there a certain water temp to wait for before winterizing? I'm in Maryland near Baltimore. This week it'll be in the low 80s and it's mid Sept.

InyoPools Product Specialist  Posted: 11/17/2015 

Family Mom - We recommend draining the pool below the skimmer. 20 psi should be adequate to blow the lines. Set your MPV to "Filter" or "Recirculate" to open the path to the return ports. You should see water movement and then bubbles in less than 5 minutes. I believe the "pre-pump check valve" you reference is a check valve installed between the pump and the skimmer to keep water from draining out the skimmer when the pump is shut off and the pump is higher than the pool surface. Most system do not have these installed. If your pool has one, you would have to blow out the skimmer line from the skimmer.

 Posted: 11/17/2015 

We are trying to use a pancake-style air compressor connected to the pump drain as noted in the steps above, but we are not seeing any bubbles out of the skimmer or return jets. We haven't yet drained the pool below the skimmer level because we had read in some places that it didn't to be done and was better for the winter cover to leave it. But now we're thinking maybe we need to do so to facilitate draining the lines. We have kept the compressor running below 20psi because we read that higher pressure could cause problems. Is that correct?
How long should it take to see some bubbles or water movement? Also, does it matter what setting the multi-port valve is on for the sand filter when doing so? If it does, what setting should it be? In a forum on another site, someone mentioned that they had to "reverse the pre-pump check valve." What is that, and is that something that needs done to make this work? We have a Pentair pump, but I don't see any valve. From what we've read, the process of blowing out the lines shouldn't be that difficult, but we don't want to cause any problems by doing it incorrectly.
I appreciate any guidance you can offer.