9 Essential Winterizing Supplies for an Above Ground Pool

When autumn leaves start to fall and the air turns crisp, the season for backyard swimming draws to a decisive close. Leaving an above-ground pool vulnerable to freezing temperatures and winter debris is a recipe for expensive structural damage come spring. Securing the right winterizing supplies now ensures the investment is fully protected against ice, wind, and algae over the long off-season.

Disclosure: As an Amazon Associate, this site earns from qualifying purchases. Thank you!

Why Winterizing Your Above Ground Pool Is Crucial

Above-ground pools are uniquely vulnerable to winter damage compared to their in-ground counterparts. Because the pool walls are entirely exposed to the elements, the water inside freezes much faster and expands outward, putting immense pressure on the steel frame and vinyl liner. Without proper preparation, this expanding ice can split seams, warp top rails, and cause catastrophic wall blowouts that ruin the entire setup.

Additionally, leaving a pool uncovered or chemically untreated over the winter creates a breeding ground for algae and invasive bacteria. When spring arrives, instead of an easy opening process, pool owners are faced with a swampy green mess that requires hundreds of dollars in corrective chemicals and hours of scrubbing to clear.

The goal of winterizing is simple: prevent physical freeze damage, keep out organic debris, and maintain water chemistry so opening next spring is painless. Investing in the right tools and following a systematic shutdown routine preserves the integrity of the pool structure and saves money on costly repairs.

Pool Cover – Robelle Supreme Winter Cover

A solid winter cover is the primary barrier defending the pool against harsh winter weather, sunlight, and heavy debris. Its main job is to keep organic matter like leaves, twigs, and dirt out of the water while blocking UV rays that stimulate algae growth. Without a heavy-duty cover, the pool water will quickly turn into a stagnant mess before the first hard freeze even hits.

The Robelle Supreme Winter Cover stands out because of its heavy-duty polyethylene construction and a dense 12×12 scrim count. This tight weave provides excellent puncture resistance and prevents water from seeping through, while the green/black color configuration blocks all sunlight to halt algae in its tracks. It comes with a heavy-duty vinyl-coated cable and a rust-resistant winch, ensuring a tight, secure fit around the perimeter of the pool wall.

Key specifications and features include: * Material: Heavy-duty polyethylene with a 12×12 scrim count (tapes per inch) * Overlap: 4-foot overlap to ensure complete coverage over the top rails * Color: Forest green top with a black underside to completely block UV rays * Included Accessories: All-weather vinyl-coated steel cable and metal winch

When purchasing, it is critical to buy a cover based on the actual pool size, as the manufacturer already includes the necessary 4-foot overlap for installation. Buying a size too large will cause excess material to flap in the wind, while a size too small will strain under the weight of winter snow. This cover is ideal for pool owners in areas that experience heavy snow and wind, but it might be overkill for mild climates that only see light rain and occasional dips in temperature.

Winter Chemical Kit – In The Swim Ultimate Pool Kit

Algae does not stop growing just because the pool is closed, especially during the warm autumn and spring transition weeks. A dedicated winter chemical kit slow-releases sanitizers and algaecides over the cold months to keep the water clear and prevent staining on the vinyl liner. This chemical defense minimizes the need for heavy scrubbing and massive chemical shocks when the pool is reopened.

The In The Swim Ultimate Pool Kit provides a comprehensive, pre-measured chemical regimen that takes the guesswork out of water preservation. This kit includes a powerful winterizer algaecide, a non-chlorine winter shock, stain preventer, and a unique slow-releasing chemical dispenser designed to float beneath the ice. The inclusion of a patented companion winter pool floater ensures that sanitizing agents are distributed evenly even when the filtration pump is turned off.

The kit is configured for specific pool volumes: * Small Kit: Up to 10,000 gallons * Medium Kit: Up to 20,000 gallons * Large Kit: Up to 35,000 gallons

Before tossing the chemicals in, the pool water must be completely balanced and free of existing active algae. These chemicals are designed to prevent growth, not cure an ongoing algae bloom, so skipping the pre-cleaning step will render the kit far less effective. This kit is perfect for pool owners who want a convenient, all-in-one chemical solution to ensure a clear spring opening, but it may not be necessary for those who prefer to buy bulk chemicals and mix their own custom closing formulas.

Pool Air Pillow – Swimline Ice Equalizer Pillow

When water freezes, it expands outward, exerting thousands of pounds of pressure against the rigid walls of an above-ground pool. An air pillow sits in the center of the pool under the cover, acting as an artificial expansion cushion. As the ice sheet forms and expands inward, it collapses the pillow instead of pushing outward against the pool walls and damaging the structure.

The Swimline Ice Equalizer Pillow is manufactured from heavy-gauge vinyl designed to withstand extreme cold without cracking or losing air. Its reinforced grommets on the corners allow for easy centering using utility ropes, preventing the pillow from shifting to one side during winter storms. By breaking up the solid sheet of ice on the surface, it also relieves tension on the pool cover itself.

Key specifications include: * Dimensions: Available in 4×4 foot, 4×8 foot, and 4×15 foot configurations * Material: Heavy-duty, freeze-resistant vinyl * Securing mechanism: Dual corner grommets for rope attachment

A common mistake is inflating the air pillow completely to its maximum capacity. It should only be inflated to about 60% to 80% full to allow room for compression; a fully inflated pillow is highly likely to pop under the intense pressure of freezing ice and heavy snow. This is an absolute must-have item for anyone living in regions that experience freezing winter temperatures, whereas pool owners in tropical climates can skip this accessory entirely.

Cover Pump – Wayne WAPC250 Pool Cover Pump

Accumulated rain, melted snow, and heavy ice on top of a pool cover create immense weight that can pull the cover into the pool or damage the top rails. A reliable cover pump removes this stagnant water before it accumulates to dangerous levels, preserving the tension of the winter cover. Removing this standing water also prevents mosquito breeding ground formation in the early spring.

The Wayne WAPC250 Pool Cover Pump features an intelligent automatic switch that turns the pump on when water levels reach 2.1 inches and off when the water drops below 0.75 inches. Its oil-free, high-flow design can move up to 3,000 gallons per hour, quickly clearing heavy water loads after sudden winter downpours. The integrated debris strainer prevents leaves and twigs from clogging the intake, ensuring uninterrupted operation.

Key specifications and features include: * Flow Rate: Up to 3,000 Gallons Per Hour (GPH) * Activation: Automatic top-sensing switch with freeze protection * Power: 1/4 HP oil-free motor with a 25-foot power cord * Debris Guard: Large intake base to prevent clogging from leaves

Keep in mind that this pump requires a standard outdoor electrical outlet and a garden hose to direct the drained water away from the pool foundation. It is also important to unplug and store the pump indoors during periods of extreme, prolonged deep freezes to prevent ice from damaging the internal impeller. This automatic pump is ideal for homeowners who want hands-free maintenance throughout the wet winter months, while those in dry climates with minimal winter precipitation may get by with a manual siphon or smaller pump.

Cover Clips – Gladon CoverLoc Jr Wall Clips

While the standard cable and winch system holds a winter cover in place, high winds can still get underneath the edges, causing the cover to billow and flap violently. This flapping can tear the cover fabric and loosen the securing cables, risking a complete cover failure. Cover clips grip the cover directly to the top rail of the pool, sealing out the wind.

The Gladon CoverLoc Jr Wall Clips are constructed from heavy-duty, UV-stabilized plastic that grips the pool wall tightly without scratching the metal frame. These clips are designed to snap over the pool cover directly onto the top rail, creating a continuous, firm hold that prevents wind from getting underneath. Their two-piece locking design provides significantly more holding power than standard single-piece plastic clips.

Key features and sizing considerations include: * Design: Two-piece male/female locking system * Material: UV-protected, impact-resistant resin * Compatibility: Fits standard metal top rails on steel-walled above-ground pools * Pack sizes: Available in packs of 12, 24, and 36

Before purchasing, check the width of your pool’s top rails, as these clips are designed for standard metal rails and may not fit extra-wide resin top rails. For maximum protection, it is recommended to install at least two clips per top rail section, placing them closer together on the windward side of the yard. These clips are a crucial upgrade for pool owners in open, windy areas who want to avoid the headache of a shredded winter cover, but they are not compatible with soft-sided, temporary frame pools.

Winter Plug – Hayward SP1022C Rubber Expansion Plug

Water left inside the return lines and plumbing of an above-ground pool will freeze, expand, and crack the PVC pipes or damage the pool wall fittings. Winter plugs seal these plumbing lines from the inside of the pool, allowing you to drain the hoses and equipment without draining the entire pool. This simple barrier prevents costly plumbing replacements come spring.

The Hayward SP1022C Rubber Expansion Plug utilizes a heavy-duty rubber body and a corrosion-resistant nylon wing nut to create an airtight seal inside the return line. As the wing nut is tightened, the rubber expands outward to grip the interior walls of the pipe, accommodating slight variations in fitting sizes. The durable construction ensures it won’t crack or degrade when exposed to chlorine and freezing temperatures.

Key specifications include: * Size: Fits standard 1.5-inch threaded or non-threaded return fittings * Material: Heavy-duty rubber with a non-corrosive nylon bolt and wing nut * Application: Seals return lines, cleaner lines, and skimmer ports

Ensure the return line is completely clean of any scale or debris before inserting the plug, as even a small grain of sand can prevent a perfect seal and allow water to slowly leak back into the plumbing. This expansion plug is the industry standard for securing return fittings, making it a mandatory purchase for any pool owner in a freezing climate, except for those using specialized proprietary filtration systems that do not use standard 1.5-inch return lines.

Skimmer Plug – Aquador 1090 Faceplate Cover

The skimmer box is highly susceptible to cracking if water enters it, freezes, and expands during the winter. A skimmer plug seals off the mouth of the skimmer from the inside of the pool, preventing water from entering the housing. This eliminates the need to drain the pool water below the skimmer line, saving valuable water and maintaining structural stability over the winter.

The Aquador 1090 Faceplate Cover replaces your existing skimmer faceplate with a specialized frame that accepts a heavy-duty plastic snap-on lid. The lid creates a completely watertight seal over the skimmer opening, allowing you to keep the pool water at its normal operating level throughout the winter. Its durable, freeze-resistant plastic construction ensures it can withstand ice pressure without warping or leaking.

Key compatibility and design specifications include: * Compatibility: Fits Hayward SP1090, SP1091, and standard Olympic/Aquador skimmers * Material: High-density, freeze-proof plastic with a rubberized sealing lip * Method: Snap-on lid design that eliminates the need to drain the water below the skimmer

Installing the Aquador faceplate requires unscrewing the original skimmer faceplate, which should be done during the initial pool closing process. It is vital to match the model number exactly to your specific skimmer brand to ensure a leak-proof seal. This system is perfect for pool owners who want to avoid draining their pools below the skimmer line every autumn, but it is not suitable for those who prefer temporary, non-screw-in skimmer blockades.

Pool Cover Wrap – Blue Torrent Winter Cover Seal

Even with cables and clips, high winds can still find gaps along the perimeter of an above-ground pool cover, threatening to lift it off entirely. Pool cover wrap acts like heavy-duty plastic stretch wrap, binding the cover tight against the outer pool wall to seal out wind and debris. This extra layer of defense ensures the cover remains immobile during the worst winter blizzards.

The Blue Torrent Winter Cover Seal is formulated with specialized UV inhibitors to prevent the plastic from degrading under intense winter sunlight. It features high-strength, puncture-resistant stretch film that clings to itself, creating a clean, tight, multi-layered band around the top edge of the pool. This wrapping action also prevents dirt, dust, and pests from nesting under the cover lip.

Key performance details: * Dimensions: 80-gauge thickness, typically sold in 500-foot or 1000-foot rolls * Material: Self-clinging polyethylene with integrated UV inhibitors * Function: Seals the perimeter gap between the pool cover and the outer wall

When applying the wrap, it is best to have two people work together to maintain consistent tension while walking around the perimeter of the pool. Applying three to four full wraps around the upper pool wall is generally the sweet spot for maximum holding power. This wrap is an excellent, inexpensive security measure for pool owners in high-wind regions, but it is a single-use item that must be cut off and discarded during spring opening.

Leaf Net Cover – Robelle Oval Leaf Net Cover

If your backyard is surrounded by deciduous trees, autumn leaves will quickly blanket your winter cover, turning into a heavy, decomposing mush by spring. A leaf net cover sits on top of your standard winter cover to catch falling leaves before they can decay. Once the trees have finished shedding their leaves, you simply lift the net off, leaving a clean winter cover underneath.

The Robelle Oval Leaf Net Cover is made from a durable, lightweight polyethylene mesh that allows water to pass through while catching even the smallest leaves and twigs. It features a heavy-duty binding around the edges with brass grommets and includes a cable and winch to secure it over the primary winter cover. This mesh design prevents water weight from accumulating on the net itself, making it easy to pull off.

Key specifications include: * Material: Lightweight, high-strength polyethylene mesh * Overlap: 3-foot overlap for secure placement over the winter cover * Included Hardware: Heavy-duty winch and vinyl-coated cable * Mesh Density: Tight weave optimized for trapping wet leaves without ripping

The leaf net must be removed before the first major freeze of the winter. If the leaves freeze into the ice sheet on top of the pool, the net will become trapped and cannot be removed without tearing the mesh. This tool is an absolute lifesaver for pool owners with heavy tree canopy coverage, but it is unnecessary for those with open yards devoid of nearby trees.

How to Balance Pool Chemistry Before Closing

Closing a pool with unbalanced water chemistry is a recipe for liner staining, metal corrosion, and rampant algae growth by spring. The chemical balancing process should begin roughly one week before you plan to physically close and cover the pool. This lead time allows the chemicals to fully circulate and stabilize throughout the entire volume of water.

Start by testing and adjusting the Total Alkalinity (TA) to between 80 and 120 ppm, followed by balancing the pH levels to a range of 7.2 to 7.6. If the pH is too high, your winter sanitizer will lose its effectiveness; if it is too low, the acidic water will slowly etch the pool’s metal components and degrade the vinyl liner. Next, ensure Calcium Hardness is sitting between 200 and 400 ppm to prevent the water from drawing calcium directly out of the pool materials.

Once the baseline chemistry is set, shock the pool with a high-quality chlorine or non-chlorine shock to kill off any microscopic organic matter. Let the filtration system run for at least 24 hours after shocking before adding your winterizing chemical kit. Taking these precise steps ensures the winter chemicals can do their job effectively, keeping the water crystal clear until the warm weather returns.

Pro Tips for Securing Your Cover Against Heavy Wind

Wind is the ultimate enemy of an above-ground pool cover, and relying solely on a standard cable is rarely enough in storm-prone regions. To truly windproof your pool, you must eliminate any gaps where wind can slip underneath the cover edge. Once air gets beneath the cover, it acts like a parachute, lifting the material and putting extreme stress on the pool frame and securing straps.

One highly effective technique is to slightly offset the height of your pool air pillow and leave a small amount of water on top of the cover. While a cover pump is essential for preventing excessive water weight, keeping a very thin layer of water (about half an inch) on the cover helps weigh it down against updrafts. Combine this with a tight wrap of winter cover seal around the top circumference to eliminate wind entry points completely.

Another pro tip is to use water bags or wall bags designed specifically for above-ground pools if your top rails allow for it. Never use bricks, milk jugs, or concrete blocks to weigh down the cover; if these heavy, abrasive items slip into the pool, they can easily puncture the vinyl liner or crack the structural wall.

Conclusion

Taking the time to properly shut down and secure your above-ground pool with the right winterizing supplies pays massive dividends when warm weather returns. By choosing quality covers, plugs, and chemical kits, you protect your backyard investment from harsh winter elements and costly structural repairs. When spring finally arrives, you will be rewarded with a quick, hassle-free opening and crystal-clear water ready for another season of fun.