Closing an above-ground pool for winter is similar to closing an in-ground pool but with a few important differences: vinyl liner protection is critical, the pump and filter typically come off the pool entirely for indoor storage, and the wall integrity needs more attention. Here’s the full step-by-step.
When to close
When water temperature drops below 65°F sustained. Closing too early in warm water means an algae bloom under the cover. Closing too late risks freeze damage to thin pump and filter housings.
Step-by-step
pH 7.4–7.6, alkalinity 80–120 ppm, calcium hardness 150–250 ppm (lower than in-ground because vinyl tolerates lower calcium). Adjust before shocking.
Anything you leave on the floor will become a stain by spring. Use a soft brush for vinyl liners.
Run pump 8 hours after shocking. Add winter algaecide.
Drain to 4–6 inches below the skimmer mouth. This prevents water from freezing in the skimmer and cracking the housing.
Above-ground pumps and filters are not built for freeze exposure. Disconnect plumbing, drain the units completely, and store them indoors (garage, basement, shed). Keep all small parts (gaskets, drain plugs, baskets) together.
Install winter freeze plugs in the suction port and return port at the pool wall. These prevent water from entering the lines and freezing.
Inflate an air pillow about 1/3 full and float it in the center of the pool. The pillow flexes as ice forms in the pool, absorbing pressure that would otherwise push outward on the walls.
Solid winter cover: drape over the pool and secure with the cable and winch tightener around the perimeter. Use cover clips every 3–4 feet to keep wind from lifting the edges.
Place an automatic cover pump on the cover to remove rain and snowmelt before it overloads the cover.
Above-ground closing chemicals
Durachlor Closing Shock
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CoverBlast Non-Freeze Hose
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Durachlor Chlorine Stabilizer
Shop NowTips specific to above-ground pools
- Inspect the top rail and uprights for rust before close. Address small spots now; full rail damage means liner replacement next spring.
- Don’t drain the pool fully. An empty above-ground pool can collapse under wind load. Leave water in for stability.
- Bring the pool ladder, hand-rails, and any auxiliary equipment indoors. Aluminum corrodes in winter weather.
If you’d like PST Pool Supplies to put together a complete above-ground closing pack, send your pool dimensions and we’ll bundle shock, cover pump hose, stabilizer, and any freeze plugs you need.