Effective Way To Winterize Your Above Ground Pool

Nothing feels better than a dip in the pool on a hot summer day, but what are you supposed to do with your pool when it’s too cold to swim?

Pool maintenance is never fun, but winterizing your above ground pool is a simple process that saves you a lot of hassle when it’s time to reopen your pool again next summer.

If you live in an area where water freezes during the winter, or if you won’t be swimming for a few months straight, you should winterize your above ground pool. 

Winterizing protects your pool components from freeze damage, keeps your pool cleaner, and maintains the water quality better during the offseason. You should winterize your pool as soon as temperatures drop below 50 degrees. 

Less cleaning and a longer-lasting pool sounds like a win-win! Winterizing an above ground pool is a normal part of good pool maintenance. You can even do it yourself, with the right equipment and instructions.

Let’s dive right in and look at why you should winterize your pool, the risks of NOT winterizing it, and everything you need to know to get started. 

Benefits of Winterizing Your Above Ground Pool 

Above ground pools should always be winterized if they’ll be out of use for long periods of time. Even if you don’t experience freezing temperatures, winterizing is prepping your pool to sit unused for months at a time.

If you have an inflatable above ground pool, you can empty it out and take it down for the winter. But if your above ground pool is non-inflatable, leaving it empty can cause more problems than it solves.

The winterizing process makes it much easier and cheaper to get your pool ready for use when spring rolls around again. Prevention is always better than a cure. Winterizing prevents some of the big issues that happen with unused pools exposed to the elements.

What Happens if You Don’t Winterize Your Above-Ground Pool?

If you choose not to winterize or forget to do it, there are 3 things that can happen:

  1. Freeze damage to the pipes and filter system
  2. Overgrowth of bacteria and algae
  3. Dirt and debris buildup throughout the offseason

You can reduce your cleanup time and keep your pool is better shape by winterizing before the offseason.

Winterizing makes it easier to reopen your pool after it’s been sitting unused for a while. Is the benefit worth the cost? To figure that out, you first need to know how much it costs.

Above Ground Pool Winterizing Costs 

The cost of winterizing an above ground pool will vary based on the size of the pool and if you hire a company or do it yourself.

On average, it costs between $150-$200 to winterize an above ground pool with its basic filtration system. Pools with center drains, stairs, tight custom fitted covers, or other specialty equipment will cost more to winterize because they require more time.  

If you don’t already have a pool cover, you’ll also need to purchase this separately. Winter covers for above ground pools cost between $50-$250 and last anywhere from 3 to 15 years, depending on what they’re made of and how harsh your winters are. 

How To Winterize Your Above-Ground Pool: 

Before you start winterizing your pool, you need few supplies:

  • Winterizing kit
  • Pool test kit
  • Pool clarifier (such as a winter pill)
  • Skimmer cover
  • Winter pool cover with cable, winch, and clips or water bags
  • Plugs for filter pipes and water input lines
  • Pool air pillow (if not included in your winterizing kit)
  • Pool antifreeze (if necessary for you filter)

Winterizing kits usually contain pH increaser, alkalinity increaser, calcium hardness increaser, pool shock, and algaecide. 

Step 1: Clean the Pool 

The first thing you have to do before closing your pool for the winter is give it a thorough cleaning. You need to do this first so that the filter can catch any small particles you dislodge while cleaning.

When you’re cleaning the pool to close it, you want to go the extra mile. Like with spring cleaning, take the opportunity to clean all the nooks and crannies you’d normally leave.

Start by removing any pool accessories or attachments, including the ladder or stairs. Then, get your net and remove any debris floating on top of the water.

Next, grab a sponge and clean around the edges of the pool, paying special attention to the corners and around the seams. Remove any mold, algae, or dirt you see.

Use the pool vacuum to thoroughly clean the sides, then the bottom. Vacuum the bottom 2-3 times to make sure you get as much dirt as possible.

The last thing you should do is remove and clean out your pool skimmer. Wait a little bit between vacuuming and cleaning the skimmer so there’s time for it to catch whatever you put into the water while cleaning.

Step 2: Test and Balance the Water Levels

Now that you’ve gotten the dirt out of your pool, you need to check the chemical levels and balance them out. It’s important to do this BEFORE you start adding anything extra so you’re starting at the right place and don’t accidentally overdo it.

Purchase a pool test kit that includes tests for chlorine, pH, alkalinity, calcium hardness, and cyanuric acid (chlorine stabilizer). These are the ranges you’re looking for with each chemical:

Chlorine2.0-4.0 ppm
Alkalinity80-120 ppm
Calcium hardness200-400 ppm
Cyanuric acid30-50 ppm

If any chemicals are not in their ideal range, balance them out with the winterizing kit chemicals. If you need to correct the alkalinity of the water, do it before you adjust the pH level. Increase alkalinity with an alkaline increaser or reduce it with muriatic acid. 

Step 3: Control the Phosphate Levels 

After balancing out your pool chemical levels, the next thing to check is the phosphate levels.

Phosphates are a natural compound that’s often found in water. While it’s not harmful to humans, it’s a great source of nutrients for algae and can cause rapid algae growth.  

There’s an ongoing debate about whether to use phosphate remover in your pool or not, with some experts recommending it for winterizing and others saying it’s completely unnecessary.

Phosphate remover can be helpful if you have regular issues with algae growth. Check your phosphate levels before adding anything. If the phosphate levels are above 500ppb, use phosphate remover. An ideal range is 100-125ppb.

Most phosphate removers work at a ratio of 1oz. per 5,000 gallons of water.

If you’re consistent with pool maintenance and chemical levels, you probably won’t need phosphate removers because the algae will be under control and the phosphate levels will already be low. 

Step 4: Add Stain Prevention Treatment 

Water sitting in your pool undisturbed for months can lead to stains and scale buildup around the sides. To keep this from happening, you need to add stain prevention treatment as part of your winterizing routine.

Add 1 oz. of treatment for every 1,000 gallons in your pool. Pour it straight into the water around the edges of the pool and let it dilute to spread around.

If you want to spread it a little more quickly, you can also add it to your filter area and allow the pump to push the treated water into the pool.

Stain prevention treatments work against metallic stains, not algae stains. For algae stains, you need to take a few different preventative measures as well as adding algaecide. 

Step 5: Prevent Algae Growth 

Algae is the bane of pool owners because it thrives in warm, settled water. To keep it at bay while your pool is unused, you can take a few preventative steps.

At this stage, you’ve already taken one of those steps: balancing your pool chemicals. Keeping your chlorine levels properly balanced is key to preventing algae from starting to grow.

If you want to make sure the chlorine levels last as long as possible through the winter, aim for the higher side of the ideal range, closer to 3.0-4.0 ppm.

The next preventative measure you should take is adding algaecide to your pool water. What this does is kill any existing algae before it has a chance to grow. Algaecides are normally sodium bromide based.

For winterizing, add 12 oz. of algaecide per 10,000 gallons of water. This is around 4 times more than you’d add during your regular maintenance. 

Step 6: Shock Your Pool 

Once you’ve added your algaecide, it’s time to shock the pool. Pool shock is a strong chemical agent that’s similar to bleach. What it does is disinfect and essentially sterilize your pool water to get you back to stable chemical levels.

Always wear protective gear when you’re using pool shock. Put on rubber gloves, safety glasses, and long clothing that covers your arms and legs. If any pool shock touches your skin, make sure you wash that area immediately.

There are liquid and granule versions of pool shock. For granule pool shock, add 1 lb. of per 10,000 gallons of water. For liquid pool shock, add 1 gallon per 10,000 gallons of water. If you have an algae issue in your pool, double your normal dose of shock.

Granular shock should be mixed into a 5-gallon bucket of water before you add it to the pool water. If you can, add the pool shock in the evening and let it do its work overnight before you turn off the pump and attach the cover.

Step 7: Lower The Pool Water 

Unless you have a sealing skimmer cover, you need to lower the water level in your pool to around 3 inches under the skimmer entry valve.

Don’t empty your above ground pool completely! Leaving it empty exposes the liner to air and the elements all winter long, causing it to wear out more quickly and potentially leading to damage from snow and ice.

All pool pumps have a 3-way valve on top where the water enters the pump. To drain pool water in a controlled way, shut off the pump, close the water input line valve, and open the drainage valve on the top of the pump.

Once the water is drained, disconnect the pipe going into the pool and plug the hole.

Step 8: Clean the Pump Filter 

Pump filters need to be removed, cleaned, and stored indoors during the winter. The first step is always to turn off the pump and disconnect it from the power source. Afterwards, you need to clean the filter itself.

There are 3 types of pool filters, with each one cleaned a little differently:

Sand filters

To clean a sand filter, do a quick backwash first. Then, set the valve on top of the filter to the “winter” position. Look at the bottom of the filter for the drainage valve and drain all the water out. Lastly, remove the pressure gauge and site glass to store them inside.

Cartridge filters

Open the top valve to release pressure and remove the bottom drainage plug to empty all the water.

Take the cartridge filter out and gently hose it off to remove debris. Leave it to soak in filter cleaning solution for at least 12 hours before rinsing it off and drying it.

Disconnect all pipes coming in and out of the filter, then hose out the inside of the filter tank and wipe it down.  

Diatomaceous earth (DE) filters

Pump the handle on top of the filter 8-10 times, pushing down slowly and pulling it up quickly.

Open the valve or drain plug at the bottom of the filter to empty the tank. Then, disconnect all pipes, hoses, and valves coming in or out of the filter.

Take the top cover off the filter and remove the internal filter elements (it might be a cartridge, grid, or something similar). Rinse filter elements and allow them to dry before taking them inside for storage.

Above ground pool pumps MUST be stored inside for the winter to prevent freeze damage. 

Step 9: Add a Winter Pill 

Winter pills are a great way to keep your pool stable for longer. These are capsules that slowly release winterizing chemicals like algaecide and stain prevention.

One winter pill works for pools up to 30,000 gallons. All you have to do is insert the small plastic valve, poke holes in the designated spots along the surface of the capsule, and throw it in the pool water.

While a winter pill isn’t a necessary part of winterizing above ground pools, it’s going to make it a lot easier to open the pool again in spring. This should be the last thing you do before you put the cover on your pool.

Step 10: Put on the Winter Cover 

Before you finally put your winter cover on, skim any leaves or debris off the top of the pool water one last time.

You have the option to put an air pillow under the cover as well, if you’re worried about ice damage. Place the air pillow into the center of the pool, underneath the cover.

To place the cover on correctly, it needs to be firmly attached around the edges. First, lay the cover out over the top loosely to align it. Then, run your cover cable through the eyelets around the edges of the cover and tighten it with your cable winch.

For above ground pools built into a deck area, attach water bags around the inside edge of the cover to secure it in place. If it’s a standalone pool, use cover clips to secure it to the pool sides.

If you’re using a safety cover, attach it overtop your winter pool cover.

The Best Above Ground Pool Winterizing Kits 

Winterizing kits include everything you need to get your pool ready for the offseason. While you can buy all the same things separately, it’s often cheaper and easier to buy a winterizing kit.

The chemicals you need will come in the right quantities, so you don’t end up buying more than you need. You’re also sure to get the right chemicals without having to buy them all individually.

Winterizing kits are available based on your pool size. These are some of the most popular kits for above ground pools:

Kit NamePricePool Size Ranges (Gallons)Standout Feature
In the Swim Closing Kit$26.99-$58.997,500-35,000Great instruction booklet included
Doheny’s Ultimate Winterizing Kit$36.34-$76.497,500-35,000Budget & advanced kits available
Rx Clear Winter Pool Closing Kit$38.94-$60.9210,000-45,000Long-lasting results

Choose a kit that’s built for you pool size. If there’s no kit that matches your pool size exactly, opt for the next size up. 

Should You Hire Someone To Close Your Pool? 

The pool closing process is complex. If you don’t feel confident doing it yourself, you can hire a professional to do it for you.  

Although it’s cheaper to do it yourself, the tradeoff for pool closing is cost versus the risk of doing it wrong. 

Hiring a professional doesn’t guarantee a job well done, but you do get a little more security working with an experienced individual or company than you would if you do it yourself without any prior experience.  

 Cost RangeTime
DIY Pool ClosingWinterizing kit: $26-$76Testing kit: $7-$60Total: $33-$1363-8 hours
Hiring a ProfessionalLabor + Supplies: $150-$4002-4 hours

Many pool owners share the sentiment that you should hire a professional to close your pool the first time. Watch what they do, ask questions, and take notes so you can do it yourself next year.


If you want your above ground pool to last as long as possible, winterizing is a must. Taking the right steps in the right order will keep your pool in good condition and make it super easy to open your pool back up in the spring.

Although it’s more expensive to work with a professional, you may be able to negotiate a discount with a local company if you purchase the supplies yourself and clean the pool before they come.