How to Winterize an Above-Ground Pool: Step-by-Step Closing Guide
Winterizing an above-ground pool is not just about throwing on a cover and hoping for the best. A good winter closing protects the liner, pump, filter, hoses, skimmer, return fittings, cover, and pool walls from freezing weather, standing water, leaves, and algae.
The basic process is simple: clean the pool, balance the water, add winter chemicals, lower or protect the water level as needed, disconnect and drain equipment, install a pool pillow if freezing temperatures are a concern, secure the winter cover, and check the cover through winter.
This guide is written for above-ground pool owners using chlorine or saltwater systems. It is especially useful if you are closing a round, rectangular, oval, steel-wall, metal-frame, Intex-style, or Bestway-style above-ground pool and want a clear checklist before winter arrives.
Quick Answer: How Do You Winterize an Above-Ground Pool?
To winterize an above-ground pool, clean the water first, balance the pool chemistry, shock the pool, add winterizing chemicals, lower the water level or protect the skimmer according to your pool and cover instructions, disconnect and drain the pump and filter, remove accessories, protect the skimmer and return openings, add a pool pillow if freezing is likely, then secure a properly fitted winter cover.
For the easiest spring opening, do not treat the cover as the only winterizing step. A better setup usually includes the right winter cover, balanced water, a winterizing kit, a pool pillow in freezing climates, and a cover pump or leaf net if leaves and standing water are a problem.
Above-Ground Pool Winterizing Checklist
Quick summary: winterizing an above-ground pool works best when you treat it as a full system: clean water, balanced chemicals, protected equipment, a properly fitted cover, and regular winter checks.
Before You Start: Read This First
Before closing your above-ground pool, check your pool manual, filter manual, salt system manual, and winter cover instructions. Different pool types can have different winterizing requirements, especially soft-sided frame pools, steel-wall pools, and pools used in freezing climates.
Some soft-sided or seasonal frame pools may need to be drained, disassembled, and stored indoors if your area gets freezing temperatures. Other above-ground pools are designed to stay up year-round when winterized correctly. Do not assume every above-ground pool should be closed the same way.
Also, a standard winter cover is not the same as a safety cover. A winter cover helps protect the pool from leaves, debris, dirty water, sunlight, and off-season exposure. It should not be treated as a child or pet safety barrier.
When Should You Winterize an Above-Ground Pool?
The best time to winterize an above-ground pool is when the weather has cooled down consistently, but before the first hard freeze.
As a general rule, wait until the water is no longer warm enough to encourage fast algae growth. Many pool owners close when temperatures are consistently around the low-to-mid 60s°F or below. Closing too early can trap warm water under the cover and increase the chance of algae. Waiting too long can leave your pump, hoses, fittings, or skimmer exposed to freezing weather.
The exact timing depends on your region. A pool owner in New York, Pennsylvania, Michigan, or Wisconsin may need to close much earlier than someone in Georgia, Texas, or the Carolinas.
Supplies You Need to Winterize an Above-Ground Pool
You do not need a complicated setup, but you do need the right supplies before you start. The last thing you want is to half-close the pool and then realize you are missing plugs, a cover pump, or winter chemicals.
Here is the basic above-ground pool winterizing checklist:
Pool test strips or liquid test kit
Pool brush, skimmer net, and vacuum
Chlorine shock
Winterizing kit or winter algaecide
Winter cover matched to your pool shape and size
Cable and winch, cover clips, straps, stretch wrap, or cover weights
Pool pillow for freezing climates
Cover pump or siphon pump for solid winter covers
Skimmer plug, return plug, or skimmer plate
Shop vac or air compressor if you need to blow out lines
Storage bin for plugs, clamps, hoses, fittings, and small parts
Dry indoor storage space for pump, filter, ladder, hoses, and salt cell
Once you have the essentials ready, the rest of the closing process becomes much easier. You do not need every winterizing accessory for every pool, but you do need the right combination for your pool type, local weather, and the problems you usually deal with over winter.
Helpful Winterizing Gear
Quick summary: the most important winterizing products are the winter cover, closing chemicals, equipment plugs, pool pillow, and a cover pump if you use a solid cover.
Step 1: Clean the Pool Before Closing
Start with the cleanest water possible. Leaves, dirt, algae, pollen, and fine debris become harder to deal with once the pool is covered for winter.
Skim the surface, brush the walls, vacuum the floor, and clean around the skimmer and return areas. If your pool has visible algae, do not just cover it and hope winter will solve the problem. Treat the water first, run the pump, and close only when the pool is clean and clear.
Clean the filter before closing too. Backwash a sand filter, rinse or clean a cartridge filter, and remove as much trapped debris as possible. The cleaner the system is before closing, the easier your spring opening will be.
Step 2: Test and Balance the Water
Balancing the water before winter helps protect the liner, fittings, equipment, and pool surface while the pool sits unused.
Test the water before adding winter chemicals. You want the pool in a normal balanced range first, then you can shock and add closing chemicals according to the product label.
Quick summary: balance the water before adding winter chemicals. Your pool manual and chemical label should always override generic target ranges.
Step 3: Shock the Pool and Add Winter Chemicals
Once the water is balanced, shock the pool to help remove contaminants before the cover goes on. Follow the shock product directions for your pool size and water volume.
After shocking, run the pump long enough to circulate the water properly. Do not rush this step. Give the shock time to mix through the pool before adding other winter chemicals.
A winterizing kit can make this step easier because it usually combines closing chemicals designed to help protect the water during the off-season. For a simple all-in-one option, see the POOLHACKER Winterizing Kit Review.
Do not mix chemicals together in a bucket unless the product label specifically tells you to. Add each chemical separately, follow the label directions, and avoid dumping chemicals directly onto the liner.
Step 4: Lower the Water Level or Protect the Skimmer
This is one of the steps where above-ground pool owners need to be careful.
Some pools and covers require the water to be lowered below the skimmer or return. Others may use a skimmer plate, skimmer plug, or return plug so the water does not need to be lowered as much. Your cover instructions matter here.
Do not drain an above-ground pool too far unless the manufacturer tells you to. The pool walls and liner still need water support. Draining too much can cause liner movement, wrinkles, wall stress, or structural problems.
For many above-ground pools, the goal is not to empty the pool. The goal is to protect the skimmer, return, plumbing, pump, filter, and cover setup from freeze damage.
Water level tips
Follow your pool and winter cover instructions first
Protect the skimmer and return openings
Keep enough water in the pool to support the liner and walls
Do not leave hoses, pumps, or filter parts full of water
Use a skimmer plug, return plug, or winterizing plate where appropriate
Use a cover pump later if standing water collects on a solid cover
Once the water level and pool openings are handled, move straight to equipment protection. The skimmer and return are only part of the freeze-risk; hoses, pumps, filters, salt cells, and fittings can also crack if water is left inside them.
Step 5: Remove Accessories, Hoses, and Equipment
Remove anything that does not need to stay in the pool over winter.
Take out ladders, steps, solar covers, floats, pool toys, cleaners, skimmer baskets, and loose accessories. Wash and dry them before storage so they do not sit all winter with moisture, dirt, or algae on them.
Disconnect hoses from the pump, filter, heater, chlorinator, salt system, skimmer, and return fittings. Drain the hoses fully and store them indoors if possible.
For the pump and filter, turn off power first. Remove drain plugs, drain out water, clean the parts, and store the pump and removable equipment in a dry place where freezing is less likely.
If you have a cartridge filter, clean and dry the cartridge before storing it. If you have a sand filter, follow the filter manual for draining and winter storage. If you have a saltwater pool, remove and store the salt cell according to the salt system instructions.
Step 6: Drain or Blow Out the Plumbing
Any water trapped inside hoses, fittings, pump parts, filter tanks, chlorinators, heaters, skimmers, returns, or hard plumbing can freeze and expand.
For simple above-ground pools with flexible hoses, this usually means disconnecting the hoses and draining them fully. For pools with more permanent plumbing, you may need to blow out the lines with a shop vac or compressor and then plug the openings.
Use pool winterizing plugs or a proper skimmer winterizing plate where needed. If you use pool antifreeze, use only pool-safe antifreeze and follow the label. Do not use automotive antifreeze in pool plumbing.
This is the step where a professional is worth considering if you are unsure. A bad plumbing winterization can be more expensive than the closing itself.
Step 7: Add a Pool Pillow in Freezing Climates
A pool pillow is mainly useful in areas where the pool water can freeze.
When water freezes, it expands. In an above-ground pool, that expanding ice can push outward against the pool walls. A winterizing pool pillow gives the ice a softer area to compress into, helping absorb some of that expansion pressure instead of letting the ice push directly against the pool wall.
A pool pillow can also raise the middle of a winter cover slightly, which may help reduce one deep sagging area in the center. But the main winter purpose is ice expansion support.
Inflate the pillow only partway, usually around 60% to 80%, unless the pillow instructions say otherwise. If it is inflated too hard, it has less room to compress. Tie it near the center of the pool and install the winter cover over it.
A pool pillow does not replace a winter cover, and it does not remove standing water. For more detail, see the POOLHACKER Pool Pillow Review.
Step 8: Install the Winter Cover
Choose a winter cover that matches your pool shape and size. Round, rectangular, and oval above-ground pools need different cover options, and oval pools can be especially tricky because some covers are made for soft-sided or metal-frame pools while others are made for steel-wall oval pools.
For help choosing by pool shape, see the Best Winter Covers for Above-Ground Pools guide.
When installing the cover, spread it evenly over the pool and make sure it has proper overlap. Secure it with the cable and winch, straps, clips, stretch wrap, cover weights, or the fastening system that came with the cover.
Do not treat a solid winter cover like a rigid platform. It should be secured properly, but it should not be expected to hold heavy standing water or snow without support. Use a cover pump to remove standing water from a solid cover when needed.
For windy areas, extra support can help. Cover clips, stretch wrap, and cover weights can reduce lift and movement, especially on exposed above-ground pools.
Step 9: Use a Leaf Net if Trees Are a Problem
A leaf net is not a replacement for a solid winter cover. It solves a different problem.
A solid winter cover helps block dirty water, debris, sunlight, and leaves from getting into the pool. A leaf net catches leaves and larger debris before they break down on top of the solid cover. For a round-pool option, see the Blue Wave Leaf Net Pool Cover review.
Pro tip: if your pool sits near trees, use a leaf net over a solid winter cover during heavy leaf fall. The leaf net catches most of the leaves and larger debris, so you can lift them away before they rot on the cover. After that, you are mostly left with standing water on the solid cover, which can then be removed with a pool cover pump.
The best sequence for leafy yards is solid winter cover first, leaf net over the top during heavy leaf fall, then cover pump after the leaves have been removed.
This setup is especially useful if you normally open the pool in spring and find a heavy layer of wet leaves, sludge, and dirty water sitting on top of the cover.
Step 10: Manage Standing Water During Winter
If you use a solid winter cover, rainwater and melted snow can collect on top. A small amount of water is normal, but heavy standing water can stretch the cover, pull at the edges, and make spring cleanup much harder.
A pool cover pump helps remove that water before it becomes a bigger problem. Some owners use automatic cover pumps, while others prefer a manual electric pump or siphon-style pump.
For most solid winter cover setups, a cover pump is one of the most useful add-ons. It does not replace the cover, pillow, or winter chemicals. It simply helps manage the water that sits on top of the cover.
For options, see the Best Pool Cover Pumps for Winter Covers guide.
Chlorine vs Saltwater Pool Winterizing
Chlorine and saltwater above-ground pools follow the same basic winterizing process, but saltwater pools need extra attention around the salt cell, salt level, and control unit.
Quick summary: saltwater pools still need the same winter cover, water balance, plumbing, and equipment protection steps. The main difference is caring for the salt cell and following the salt system manual.
What Each Winterizing Product Actually Does
A lot of above-ground pool owners get confused because winterizing products overlap visually, but they do not all do the same job.
A winter cover, leaf net, pool pillow, cover pump, stretch wrap, and winterizing kit each solve a different winter problem.
Quick summary: the best winter setup is not one product. It is the right combination of cover, chemistry, equipment protection, ice support, and water management.
Common Above-Ground Pool Closing Mistakes
Even a good winter cover cannot fix a poor closing. These are the mistakes that usually cause the biggest problems in spring.
Closing too early
If the pool is still warm, algae has a better chance of growing under the cover. Wait until the weather has cooled consistently, but do not wait until freezing weather is already here.
Covering dirty water
Leaves, algae, dirt, and pollen do not disappear over winter. Closing a dirty pool usually means opening a messier pool in spring.
Skipping water balance
Unbalanced water can affect the liner, fittings, equipment, and water clarity. Balance before shocking and adding winter chemicals.
Draining too much water
Above-ground pools still need water support. Do not drain too far unless your pool manufacturer specifically instructs you to.
Leaving water in equipment
Water left inside pumps, hoses, filters, fittings, heaters, or chlorinators can freeze and crack parts.
Forgetting the salt cell
Saltwater pools need the salt cell cleaned, dried, disconnected, and stored according to the system manual.
Expecting the cover to handle everything
A winter cover helps protect the pool, but it still needs support. Remove leaves, pump off standing water, check the cable or straps, and inspect after storms.
Final Winterizing Checklist
Before you walk away for the season, check each of these:
Pool water is clean and clear
pH, alkalinity, chlorine, and other key levels have been tested
Pool has been shocked according to product directions
Winterizing kit or closing chemicals have been added
Water level has been adjusted or skimmer has been protected
Pump, filter, hoses, salt cell, and accessories have been drained and stored
Skimmer and return openings are protected
Pool pillow is installed if freezing is a concern
Winter cover is centered, secure, and properly fitted
Leaf net is added if trees are a problem
Cover pump is ready for standing water
Small parts, plugs, clamps, and fittings are stored together
You know what needs to be checked after storms
Once everything is checked, take a few photos of the cover, skimmer area, pump and filter setup, and stored parts. This gives you a useful reference for spring opening and makes it easier to spot anything that shifts after heavy rain, snow, wind, or storms.
Final Verdict
Winterizing an above-ground pool is not complicated, but it does need to be done in the right order.
Clean the pool first, balance the water, add closing chemicals, protect the skimmer and return, drain the equipment, add a pool pillow if freezing temperatures are likely, and secure the correct winter cover for your pool shape and size.
For the easiest spring opening, think beyond the cover. A solid winter cover protects the pool, a leaf net helps remove leaves, a cover pump handles standing water, a pool pillow helps with ice expansion, and a winterizing kit helps protect the water while the pool is closed.
Done properly, winterizing your above-ground pool saves you time, money, and frustration when swimming season comes back around.
Related Winterizing Guides
Use these supporting guides when you are ready to choose the winter cover, cover pump, pool pillow, chemical kit, stretch wrap, or leaf net that fits your pool setup.
FAQ
When should I winterize my above-ground pool?
Winterize your above-ground pool when temperatures have cooled consistently, but before the first hard freeze. Many pool owners close when the weather is regularly around the low-to-mid 60s°F or below, because warm water under a cover can increase the chance of algae.
Can I winterize an above-ground pool myself?
Yes. Many above-ground pool owners can winterize their own pool with the right supplies and a clear checklist. Hire a professional if you are unsure how to blow out plumbing lines, protect complex equipment, or close a saltwater system.
Do I need to drain my above-ground pool for winter?
Usually, you should not fully drain an above-ground pool unless the manufacturer tells you to. Many pools only need the water lowered to the level recommended by the pool, skimmer, or cover instructions. The pool still needs water support for the liner and walls.
How low should I lower the water in an above-ground pool?
Follow your pool and cover instructions first. Some setups lower the water below the skimmer or return, while others use a skimmer plug, return plug, or winterizing plate. Do not drain too far because above-ground pool liners and walls still need support.
Do I need a pool pillow to winterize an above-ground pool?
A pool pillow is most useful in freezing climates. It helps absorb some of the expanding force of freezing water so the ice is less likely to push directly outward against the pool walls. It can also help lift the cover slightly and reduce deep center sagging.
Do I need a cover pump for a winter pool cover?
If you use a solid winter cover, a cover pump is very useful. Rainwater and melted snow can collect on top of the cover, and a pump helps remove that standing water before it becomes too heavy or messy.
Can I use a leaf net instead of a winter cover?
No. A leaf net is not a replacement for a solid winter cover. A leaf net catches leaves and larger debris, but it does not protect the pool water in the same way a solid winter cover does. For pools near trees, a leaf net works best over a solid winter cover.
How do I winterize a saltwater above-ground pool?
Winterize a saltwater above-ground pool by following the same basic closing steps as a chlorine pool, but also follow the salt system manual. Turn off the salt system, disconnect the salt cell, clean it if needed, dry it, and store it safely indoors.
Should I shock my pool before closing it?
Yes, in most cases you should shock the pool before closing. Balance the water first, then shock according to the product label and circulate the water before adding final winterizing chemicals.
What is the biggest mistake when closing an above-ground pool?
The biggest mistake is treating the cover as the whole winterizing process. A winter cover helps, but you still need clean water, balanced chemistry, protected equipment, drained hoses or plumbing, and regular cover checks through winter.
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