How to Winterize an Above-Ground Pool
Published
Quick answer
Above-ground winterization protects both the water system and the pool structure. Clean and balance the pool, remove equipment and accessories that should be stored, follow the pump/filter/plumbing manuals, protect the skimmer and return fittings according to the pool's winterization method, and install a cover intended for that pool. Do not drain an above-ground pool simply because winter is coming unless the pool manufacturer specifically directs it.
Safety
Above-ground walls and liners depend on the pool's intended water support. Do not make large water-level changes or disassemble structural parts based on a generic internet checklist. Follow the pool and cover manufacturer instructions.
Clean the pool thoroughly
Remove leaves, fine debris, and attached growth before the cover goes on. A cleaner pool places less demand on the sanitizer during months when you will not be brushing and vacuuming normally.
Test the water before winter
Correct significant sanitizer and balance problems before closing. Use measured results and product labels rather than adding every product in a seasonal kit automatically.
Handle the skimmer and return correctly
Above-ground pools use different skimmer plates, plugs, return fittings, hoses, and winterizing devices. Follow the pool and fitting instructions for your exact setup. The objective in a freeze climate is to keep expanding ice from damaging plumbing and fittings, not to follow one universal water-level rule.
Protect the pump and filter
Drain, disconnect, or store equipment only as the equipment manuals direct. Remove water from components that are intended to be winterized dry, protect seals and drain plugs, and store removable equipment where the manufacturer recommends.
Remove accessories
Take out cleaners, ladders, removable steps, and accessories that are not designed to remain in a winterized pool. Clean and dry them before storage.
Install the winter cover
Use a cover designed for the pool's dimensions and structure. Pentair notes that an air pillow is used with some above-ground winter covers to help manage loads from rain, snow, and ice. Treat the pillow as part of a cover system, not a substitute for correct structural and cover instructions.
Check the pool during winter
A closed pool still needs inspection. Watch the cover, water accumulation, anchoring, wall condition, and surrounding drainage after storms. Correct problems before a small cover or load issue becomes structural damage.
What you may need
- Above-ground winter cover
- Air pillow when specified for the cover system
- Winterizing plugs or skimmer protection matched to the pool
- Water test kit
- Closing kit only if compatible
Products mentioned in this guide
These are product categories referenced by the guide, not tested or ranked picks. Check the product description, your pool or equipment model, and the seller listing before buying.
Winter pool cover
Pool cover selected for the pool type, dimensions, anchoring method, weather exposure, and manufacturer installation requirements.
Places to check
Above-ground pool winter air pillow
Inflatable pillow used under some above-ground winter covers. Size and use depend on the pool and cover instructions.
Places to check
Pool winterizing plugs
Model- and plumbing-size-specific plugs used as part of a proper winterization procedure. Match thread and fitting size before purchase.
Places to check
Skimmer winterizing plug or gizmo
Skimmer protection device selected to match the skimmer and the winterization procedure used for the pool.
Places to check
Comprehensive pool water test kit
A DPD/FAS-DPD style kit used to read chlorine, pH, alkalinity, stabilizer and hardness.
Places to check
Pool closing or winterizing kit
Bundled seasonal chemicals whose contents and concentrations vary. Use only products compatible with the pool system and follow each label.
Places to check
Related guides
- When Should You Close Your Pool for Winter?There is no universal closing date. Pools exposed to sustained freezing conditions need a real winterization plan, while many warm-climate pools can remain open or use a partial winter routine. Pentair advises winterization where snow, sleet, or temperatures around or below 32°F are a consistent part of winter, and its Sun Belt guidance describes year-round or partial operation in warmer climates. Use local freeze risk and the equipment manuals, not the first cool weekend, to decide.
- How to Close an In-Ground Pool for WinterA winter closing is a system-protection job, not simply putting on a cover. Clean and balance the pool first, then follow the exact equipment and plumbing winterization procedure for the installation. In freeze climates, the most consequential work is getting water out of, or safely protected within, vulnerable equipment and lines. If you cannot verify that step, hire a pool professional.
- Pool Closing Mistakes That Create Expensive Spring ProblemsThe most expensive closing mistakes happen when owners treat winterization as a cover installation instead of protection for an entire water-and-equipment system. The high-risk errors are closing with active algae or debris, guessing at chemistry, leaving freeze-prone water in equipment or plumbing, using mismatched plugs or fittings, choosing a water level without considering the pool and cover, and assuming the pool needs no attention until spring.
- What Chemicals Do You Need to Close a Pool?There is no universal list of chemicals that every pool must receive at closing. Test the water first, correct meaningful balance or sanitation problems, and then use only winterization products that are compatible with the pool surface, sanitizer, cover, and equipment. Pentair's current winterization guidance tells owners to balance the water and shock before adding winterization chemicals, but the exact products and doses still come from the measured water conditions and each product label. A bundled closing kit is a convenience, not a substitute for testing.
- Should You Lower the Water When Closing a Pool?Sometimes, but not by one universal number. Pentair's full winterization guidance says lowering water can help with freeze and overflow protection, while its Sun Belt partial-closure guidance explicitly says not to lower the water because circulation continues through the skimmers. The correct level depends on whether the pool is fully winterized or kept circulating, the cover, skimmer-protection method, pool construction, groundwater conditions, and local professional guidance.
- Pool Closing Supplies Checklist: What You Actually NeedBuy supplies from the closing plan, not the other way around. Most owners need water-testing and cleaning supplies, an appropriate winter cover, and model/plumbing-specific items for the chosen winterization method. Freeze-climate closures may also require skimmer protection, line plugs and equipment drain parts. Above-ground cover systems may use an air pillow. Chemicals depend on measured water conditions and product compatibility. Do not buy a giant kit first and then invent reasons to use every item in it.
Still not sure this is the right problem?
Answer two observable questions in the Pool Problem Finder and we’ll route you to a better starting guide. It does not confirm a diagnosis or generate chemical doses.
Use the Pool Problem FinderTwo quick questions. No account.
About this page
General reference information for pool owners. It is not a substitute for your equipment manuals, product labels, or a qualified local pool professional. Read our editorial standards.