As the summer comes to a close, it’s time to prepare your pool for the upcoming cold months. If you live in a place that gets freezing temperatures during the winter or you just want to tuck your pool in for a long winter’s nap, winterizing is a great idea. 

Closing your pool for the winter ensures that your pool and equipment won’t get damaged by frost, rust, or the harsh elements that Jack Frost might bring. This process may seem daunting, but if you take it step-by-step, it will make your life so much easier come spring. And don’t worry, we’re here to walk you through it.

When To Winterize Your Above-Ground Pool

The end of summer isn’t the worst thing in the world. There are pumpkin spice lattes to look forward to and you can finally wear your favorite boots that have been banished to the back of your closet. 

Before we can start enjoying all those pumpkin-flavored treats, however, we need to close out summer and ensure the cold doesn’t destroy our pools for the next season. Winter may be coming, but summer will always come again. 

Generally, once the temperature hits 65°F (18°C for you non-Americans) and stays below that threshold you’ll want to start the winterization process. 

You want to wait until this drop because it’s much harder for nasty flora and fauna to grow once the temperature drops. If you try to winterize too early you run the risk of having all those nasty growths thaw with the next spring’s pool season. 

How to Winterize (In 10 Easy Steps)

Step #1: Get Your Supplies Ready

The first step is to gather your winterizing ingredients. This is everything you’ll need to get the job done in just a few hours’ time. 

  • Winterizing Chemical Kit (which includes)
    • A pH increaser
    • An Alkalinity increaser
    • A Calcium hardness increaser
    • Some pool shock
    • An Algaecide
  • Clarifying enzyme supplement (recommended)
  • Above ground pool skimmer cover
  • Expansion plugs & return line plugs
  • Above ground pool winter cover
  • Cover winch and cable
  • Cover clips
  • Water bags (only if you have a walk-around deck)
  • Pool air pillow 

Step #2: Do One Final Deep Clean

Unlike your housemates in college, you can’t simply put things away dirty or leave dishes in the sink, hoping for the best. 

You’re gonna have to scrub and vacuum to get everything pristine before we close up for winter. 

A thorough cleaning now will save you some serious heartache next spring. 

Step #3: Test and Balance Your Pool Water

Starting the winter season off with a clean and balanced pool is a great way to avoid any damage to your pool liner and equipment while your pool is out of commission. It also makes opening it up next pool season a lot less messy.

Just in case you need a refresher… this includes:

  • Balancing the pH of the water (Recommended: 7.4-7.6)
  • Adjusting the Total Alkalinity levels (Between 80-120ppm)
  • Adjusting the Calcium Hardness levels (Between 200-400ppm)

Keeping your levels balanced before the shutdown will help keep your pool crystal clear and ready to dive in once spring hits. 

Because we’re closing down and aren’t going to be checking on our pool levels as often as usual, I personally like to push the levels a little bit higher than the recommended levels. This helps keep the balance throughout the entire winter season. 

Remember that natural forces will slowly disrupt your perfect balance, so it pays to throw in a little extra for winterization. Just don’t do a polar bear plunge right away or your hair may end up turning green. 

Step #4: Shock & Algaecide

Don’t forget to shock your pool! You don’t have to jump out from behind the bushes and shriek at it, but it does need to be thoroughly shocked. 

Pool shock boosts your sanitizer’s abilities. It’s like cranking up your amp to 11. Whatever shock you’re currently using will do the trick. You don’t have to go out and buy a specialized winter type. Just make sure to follow the manufacturer’s instructions and you’ll be good to go.  

Now let’s talk about our favorite green monster… not the Hulk, it’s actually algae. 

This step is dependent upon your region and only essential if you’re from an area that’s susceptible to algae growth between winter and your next pool season. Whatever algaecide you use, simply follow the recommended dose. Typically it’s going to be the same dosage you use when you first fill up your pool. 

Pro tip: To really put a damper on any unwanted growth or stains that may crop up over the winter months, consider using a clarifying enzyme treatment at this step. Adding this magic potion to your nearly-winterized pool will protect against contaminant build-up, unsightly liner stains, and will fortify your pool chemicals to prevent algae growth. 

Step #5: Clean or Backwash the Filter & Protect the Pump

Your pump is one of the most important pieces of pool equipment, and usually one of the most expensive to replace. Don’t let a momentary slip up hit you where it hurts… in your wallet.

Make sure to let your pump run for 8 hours after adding all of the chemicals and shocking your pool. This will give all of the chemicals time to do their job. Once this is complete, it’s time to thoroughly clean or backwash your filter.

Now that you’ve balanced your water and circulated, it’s time to put your pump to bed. It’s had a busy pool season ensuring your water is clean and flowing, so we have to treat it right to keep it pumping at its best.

The Pool Pump: Start by removing all drain plugs to get all of the water out of your pool pump, chlorinator, and hoses. Dry them out completely and then make sure to store them all indoors for the winter season.

The Pool Filter: You may have one of several different types of pool filters, so we’ll take you through each of them and how to protect them from the cold.

  • Sand Filter – Remove the drain plug(s) from the filter and let it completely drain of water. Set the dial on your multiport valve to “Winterize” and remove any additional parts that may be damaged by the elements. It’s a good idea to bring your filter inside for the season, but if your sand filter is too heavy, it will be fine outside as long as it’s completely drained and dry so that no freezing can occur that would crack the tank.
  • Cartridge Filter – Drain the filter completely, removing the cartridge and rinse that off with your hose. Make sure to leave all valves open on the filter and take the cartridge inside with you for the winter.
  • D.E. Filter (Diatomaceous Earth) – Drain the filter completely, leaving all of the valves open and then grab your hose to rinse off the grids thoroughly to remove any extra D.E. 

If you have a saltwater chlorination system, flip the switch to its “winter” setting on the chlorine generator. If your chlorine generator doesn’t have this handy switch, you can unscrew the endcaps of your chlorine generator in order to remove the electrolytic cell.

At the risk of sounding like a broken record here: bring your cell and, if possible, your chlorine generator inside with you this winter. The cold wreaks havoc on this type of equipment and protecting them from the elements will increase their lifespan and save you money.

Step #6: Empty the Lines & Pack Them Away

If you happen to be a pool owner in a cold climate (I mean, really cold when the temperature dips under freezing) you’re likely well aware of the damage that ice can cause to your home’s pipes and plumbing.

Failing to run the tap for a long stretch can cause havoc to your pipes inside the home and your pool’s plumbing is no exception. Even if you live in a more mild climate, it’s an important step to clean and empty your lines, just for peace of mind.

All you need to do is disconnect the line, let the water drain out, and then store them away in a safe (and dry) place for the winter. Make sure they’re all dried out before packing them away so you don’t get a nasty, moldy surprise in a few months’ time. You wouldn’t put your clothes away when they’re still wet, right? The same principle applies here. 

Step #7: Don’t Skip the Skimmer

Every pool owner’s favorite chore is, of course, fishing all of the garbage out of the skimmer.

Leaves, bugs, and all kinds of nasty bits accumulate every few days during the regular season. Can you imagine what would be in there if we left it for the whole winter? I’d rather not.

There are 2 schools of thought when it comes to your skimmer:

1. Plug it up with a cover.

2. Just remove the basket.

Personally I think using a skimmer basket is the better option. You’ll need to remove the skimmer basket and store it. Then, the cover goes right over the intake sealing off the pool from the filter elements. 

If you don’t have a skimmer cover, you’ll need to drain the pool to a level below the skimmer intake. If you encounter storms and rain coming in before the next pool season, you’ll need to keep an eye on your water level to ensure it doesn’t get high enough to flood your uncovered system.

Using the cover just makes it easier, in my opinion. 

Pro Tip: You can use your skimmer basket to hold all of those loose pool parts for easy storage and that way everything stays in one place throughout the winter. 

Step #8: Clean & Store Your Pool Accessories

Next, we need to gather up any other pool bits and baubles, clean them, dry them, and then store them.

Are you starting to see a pattern here?

Do you have a removable ladder? How about a favorite floaty chair?


Anything that hits the pool water and can now be removed, cleaned, and stored. 


There are specific pool cleaners on the market that are designed to clean pool equipment without destroying your carefully balanced chemicals from way back in Step #3. You can use these to help ensure balance come next pool season but as long as you give everything a quick rinse down before you put it back, you’ll probably be safe. 

Step #9: Inflate & Deploy Your Pool Pillow

Who doesn’t go to sleep without a pillow?

Your pool pillow is designed to prevent the junk from falling on your pool cover and weighing it down too much. It sits in the center of the pool, propping up the pool cover from underneath. This way, rain, snow, and debris roll towards the edges for easy cleanup and removal.

Never inflate your pool pillow to max capacity. The sweet spot is about three-quarters full. This gives your pillow a little give and helps prevent it from popping when the first snows start to fall. 

Pool pillows aren’t 100% necessary. This step all depends on the region you live in and how much rain/snow/debris you’ll be expecting throughout the winter. 

Step #10: Throw On Your Pool Cover

Almost there. 

Grab your pool cover and strap it down. Due to the prolonged lack of supervision that your pool gets during the winter, you may want to really strap it down. I don’t mean crank it down until it rips, but maybe add some additional ties and maybe even some winter cover clips. 

You’re going to be leaving your pool unattended for prolonged periods of time, so you want to know that the cover is not going to blow away in the wind with the next strong breeze. If you have pool decking around your above ground pool, you may also consider adding some water bags to the edge of the pool to help secure it down.

Did I say bricks or sandbags? Nope.

Whatever you use to weigh down your pool cover, make sure that it’s not going to damage your pool or cover if it accidentally gets knocked into the pool. I don’t know about you, but I’d rather not attempt to fish out a waterlogged sandbag from the bottom of my pool in the middle of winter.  

A Job Well Done

That wasn’t so bad, was it? Now you can enjoy the first sip of pumpkin spice without worrying about your pool for the next few months.

Don’t forget to test your pool water periodically during the winter, preferably every 2-3 weeks. Keep an eye on the color of your water and any staining or scaling that might be cropping up. 

With some care, some chemicals, and a bit of elbow grease, closing your pool for the season can be just one more thing you’ve checked off your list.