9 Essential Pool Closing Supplies for a Backyard Pool

As summer fades and the leaves begin to turn, the backyard pool transforms from a sparkling oasis into a critical seasonal maintenance task. Skipping steps during the autumn shutdown process is a fast track to expensive equipment damage, stained surfaces, and a swampy green mess come spring. Investing in the right closing supplies now ensures your pool remains protected against harsh winter freezes and opens beautifully next season.

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Why Proper Pool Winterization Saves You Money

Water expands by about nine percent when it freezes, creating immense hydraulic pressure that easily cracks PVC pipes and ruins expensive pump housings. Once subterranean plumbing lines rupture, locating and repairing the leak requires excavation work that can easily run into thousands of dollars. Proper winterization acts as an insurance policy, neutralizing this freeze risk before the first hard frost hits.

Algae control is another massive financial factor in seasonal pool management. Letting organic debris rot in unprotected water all winter stains vinyl liners and etches gunite finishes, requiring aggressive acid washing or premature liner replacement. Balancing the water and sealing the pool correctly means you will not spend hundreds of dollars on recovery chemicals when the weather warms up again.

How to Prep Your Pool Water Before Closing

Successful winterization starts long before you pull the cover over the pool coping. You must balance the water chemistry first, aiming for a pH between 7.2 and 7.6 and alkalinity between 80 and 120 parts per million. Failing to balance these levels before adding winterizing chemicals renders your sanitizer less effective and risks scale formation or corrosive damage to metal fixtures during the off-season.

Once balanced, shock the pool heavily to kill any lingering microscopic algae spores and organic contaminants. Let the pump run for at least 24 hours to circulate the shock completely before lowering the water level. For pools utilizing a winter cover, drop the water level below the skimmer mouth to prevent overflow issues from heavy winter precipitation.

Winter Cover – Blue Wave Bronze 15-Year Cover

A solid winter cover is the primary line of defense against organic debris and sunlight, which are the main ingredients for off-season algae blooms. Without a durable barrier, leaves, twigs, and dirt will quickly accumulate, depleting your pool chemicals and staining the interior surfaces. A high-quality cover also blocks UV rays, keeping the water dark and cool to prevent biological growth during early spring.

The Blue Wave Bronze 15-Year Cover stands out because of its rugged construction, utilizing a heavy-duty woven polyethylene scrim that resists rips and tears from falling branches. The underside is black to completely block sunlight, while the top has a UV-resistant coating to prevent degradation from direct exposure. It also features a generous 4-foot overlap, ensuring plenty of material to secure the cover even as water levels drop.

• Material: Heavy-duty woven polyethylene with UV-inhibited top coating
• Scrim Density: 8×8 per square inch for superior rip resistance
• Warranty: 15-year limited warranty
• Included: Vinyl-coated steel cable and heavy-duty brass winch

When buying, measure the actual dimensions of your pool rather than the old cover size, as proper overlap is critical for a secure fit. Keep in mind that a solid cover requires a pump to remove standing water, as accumulated weight can pull the cover into the pool. This cover is perfect for above-ground or in-ground pool owners seeking heavy-duty protection on a reasonable budget, but it is not suitable for those looking for a load-bearing safety cover designed to support the weight of pets or children.

Winter Chemical Kit – In The Swim Ultimate Kit

Pouring standard shock into a pool and hoping for the best is a recipe for a green opening in the spring. A dedicated winter chemical kit provides a timed-release system that slowly dispenses sanitizer and algaecide over the long winter months when your filtration system is completely shut off. It also prevents copper and iron stains from forming on pool walls while the water remains stagnant.

The In The Swim Ultimate Kit delivers a comprehensive blend of chemicals designed to work in synergy during cold-weather storage. The kit includes a non-chlorine shock that will not bleach vinyl liners, a powerful winterizer algaecide, and a metal stain preventer. It also features a unique slow-release winter floater filled with non-hazardous sanitizer to maintain clean water as temperatures fluctuate.

• Capacity Options: Kits available for pools up to 7,500, 15,000, and 35,000 gallons
• Formulation: Vinyl and plaster safe, non-bleaching formulas
• Key Contents: Winterizing algaecide, metal rust inhibitor, non-chlorine shock, and a winter chemical floater

For proper application, distribute the chemicals evenly throughout the pool while the pump is running, at least 24 hours before you plan to lower the water level. This ensures complete circulation and prevents concentrated chemicals from settling on the bottom and damaging the surface. This kit is ideal for pool owners who want a straightforward, pre-measured solution that removes the guesswork from chemical balancing, but it is not necessary for those who prefer to source and measure individual bulk chemicals.

Pool Air Pillow – Robelle Double Chamber Pillow

When ice forms on a closed pool, it expands outward, putting tremendous lateral pressure on the pool walls and coping. An air pillow sits in the center of the pool, acting as a compression cushion that absorbs this pressure and forces the ice to expand inward instead of outward. It also breaks up the surface tension of the water, preventing a single, solid sheet of ice from forming across the entire pool surface.

The Robelle Double Chamber Pillow is the ideal choice for this task due to its dual-chamber design. If one side happens to leak or puncture due to extreme pressure, the second chamber remains inflated to provide continuous freeze protection. Constructed from heavy-duty 16-gauge vinyl, it is built to withstand freezing temperatures without cracking or losing air.

• Material: Heavy-duty 16-gauge vinyl construction
• Dimensions: Available in 4′ x 4′ and 4′ x 8′ sizes
• Safety Features: Dual independent inflation chambers with rugged brass grommets

Only inflate the pillow to about 60 to 70 percent of its total capacity to allow room for compression when ice presses against it. Use the corner grommets to tie the pillow securely in the absolute center of the pool using durable nylon cord. This product is an absolute necessity for above-ground pool owners in freezing climates, while in-ground pool owners with mesh covers or those in non-freezing regions can safely skip it.

Expansion Plug – Swimline Rubber Winterizing Plug

After blowing water out of your pool lines, you must seal the returns and cleaner lines to prevent water from re-entering and freezing inside the pipes. Expansion plugs insert directly into the pipe openings, creating an airtight, watertight seal that holds up against winter weather. This simple step keeps your subterranean plumbing completely dry and protected all winter long.

The Swimline Rubber Winterizing Plug is engineered with heavy-duty rubber and corrosive-resistant stainless steel hardware to ensure a reliable seal. The large wing nut allows for easy, tool-free tightening, ensuring you can compress the rubber ring inside the pipe even with cold hands. Its tapered design allows it to fit snugly into a variety of pipe diameters, sealing off potential leak points.

• Material: Industrial-grade rubber body with stainless steel bolts
• Sizing: Available in sizes #00 (for 1/2-inch lines) up to #16 (for 4-inch lines)
• Adjustment: Oversized plastic or stainless steel wing nuts

Clean the inside of the pipe fitting before inserting the plug to ensure there is no debris that could break the airtight seal. Tighten the wing nut until the rubber expands firmly against the pipe walls, but avoid using tools to overtighten, which can crack plastic pool fittings. These plugs are essential for any pool owner with in-ground plumbing lines, but they are not required for simple, frame-style above-ground pools that are drained and stored indoors.

Skimmer Guard – Gizzmo Ultra Freeze Protection

Water that accumulates in the pool skimmer during winter is highly prone to freezing, which can crack the delicate plastic skimmer housing. A skimmer guard absorbs the expansion of freezing water inside the well, preventing the walls from rupturing under pressure. It also threads directly into the plumbing port at the bottom of the skimmer, sealing the line from water infiltration.

The Gizzmo Ultra Freeze Protection is a blow-molded plastic tube specifically designed to collapse when ice forms around it. This sacrificial design absorbs the expansion forces, protecting the expensive skimmer body from damage. The Ultra model features integrated 1.5-inch and 2-inch tapered threads, allowing it to screw securely into the plumbing port without requiring a separate expansion plug.

• Length: 16 inches for standard and deep skimmer wells
• Threads: Dual 1.5-inch and 2-inch male threads for versatility
• Design: Sealed, air-filled core designed to deform under ice pressure

Wrap the threads with Teflon tape before screwing the Gizzmo into place to ensure a completely watertight seal. Keep in mind that you must still use a skimmer cover plate or a winter faceplate if you want to keep water out of the skimmer entirely. This product is a must-have for in-ground pool owners in cold climates with standard skimmer configurations, but it is not suitable for pools with shallow or non-threaded skimmer wells.

Pool Cover Pump – Little Giant APCP-1700 Pump

Heavy rain and melting snow accumulate on solid pool covers, creating massive weight loads that can damage pool walls or pull the cover into the pool water. A specialized cover pump automatically removes this standing water, keeping the cover light and functional. Without it, the water weight will eventually submerge the cover, bringing dirty debris and organic material right into your clean pool water.

The Little Giant APCP-1700 Pump is a highly efficient submersible pump designed specifically for pool cover maintenance. It features an integrated mechanical float switch that automatically turns the pump on when water reaches two inches deep and shuts off when it drops below 1.5 inches. With a powerful flow rate, it clears large pools of water quickly, preventing ice sheets from forming on top of your cover.

• Flow Rate: Up to 1,745 gallons per hour at zero lift
• Power Cord: 25-foot heavy-duty power cable for easy reach
• Discharge: Standard 3/4-inch garden hose connection

Position the pump in the center of the cover where water naturally pools, and keep the intake screen clean of leaves to prevent motor strain. Make sure to unplug the pump if temperatures drop below freezing for extended periods, as frozen water inside the pump housing can damage the impeller. This automatic pump is perfect for owners of solid pool covers in rainy or snowy regions, but it is completely unnecessary for those utilizing tensioned mesh covers that drain naturally.

Pool Antifreeze – Splash Pool and Spa Antifreeze

Even after blowing air through your pool plumbing lines, small amounts of residual water can still collect in low spots and elbows. If this water freezes, it can easily split PVC pipes hidden deep underground, resulting in costly excavation repairs. Adding pool antifreeze to the plumbing lines provides a final, foolproof layer of protection against sub-zero temperatures.

Splash Pool and Spa Antifreeze utilizes a non-toxic propylene glycol base that is completely safe for pool equipment and the surrounding environment. Unlike automotive antifreeze, which is highly toxic to humans and pets, this formula can be safely introduced into pool plumbing lines without contaminating the water. It provides reliable burst protection down to -50°F, ensuring your lines remain intact even during the harshest winter snaps.

• Active Ingredient: Non-toxic propylene glycol
• Protection Rating: Burst protection down to -50°F (-46°C)
• Compatibility: Safe for copper, PVC, and plastic plumbing systems

Always blow the lines clear of water using a wet/dry vac or air compressor before pouring the antifreeze to ensure it does not become overly diluted. Never add this product directly to the pool water reservoir, as it is strictly designed for concentrated use inside plumbing lines. This antifreeze is essential for in-ground pools in hard-freeze regions, but it is not necessary for pool owners in mild climates where temperatures rarely drop below freezing.

Water Tube – Swimline Heavy Duty Double Water Tube

Solid winter covers on in-ground pools require a heavy anchoring system around the perimeter to prevent high winds from lifting the cover. Water tubes lay flat along the pool deck, securing the edges of the cover tightly against the concrete coping. This prevents leaves, dirt, and wind from getting under the cover, keeping the pool sealed and protected.

The Swimline Heavy Duty Double Water Tube is made from puncture-resistant, heavy-gauge vinyl that stands up to rough concrete surfaces. The double-chamber design prevents the tubes from rolling or sliding off sloped pool decks, ensuring they stay exactly where you place them. Additionally, if one chamber happens to leak, the remaining chamber holds enough water to keep the cover anchored.

• Material: Heavy-duty 18-gauge puncture-resistant vinyl
• Lengths: Available in 8-foot and 10-foot lengths
• Design: Double-chamber configuration to prevent rolling

Only fill the tubes to about half or two-thirds capacity to allow the water inside room to expand when it freezes. Lay the tubes end-to-end around the entire perimeter of the cover, leaving no gaps that wind could penetrate. These tubes are designed specifically for in-ground pools utilizing traditional solid winter covers, and they are not suitable for above-ground pools or pools utilizing safety covers with brass deck anchors.

Cover Seal – Blue Wave Winter Cover Shield Wrap

Above-ground pools are highly susceptible to wind damage, as high gusts can get under the overhang of the cover and lift it like a sail. This wind-flap can pull the winch and cable loose, tear the cover material, or even pull the cover completely off the pool. A cover seal wraps around the perimeter of the pool, sealing the cover edge tightly against the outer pool wall to block the wind.

Blue Wave Winter Cover Shield Wrap is a high-performance stretch film with specialized UV inhibitors that prevent it from breaking down in direct sunlight. It clings tightly to itself and the pool wall, creating an airtight band that locks the cover in place. The film is highly puncture-resistant, ensuring it survives winter winds and heavy snow loads without unraveling.

• Roll Dimensions: 80 feet long by 20 inches wide
• Material: Heavy-duty polyethylene stretch film with UV inhibitors
• Application: Clings directly to metal, resin, and vinyl surfaces

Ensure the pool wall and cover are clean and dry before wrapping to get the best adhesion and grip. Wrap the pool at least three to four times around, pulling the film taut to create a durable, wind-resistant band. This seal wrap is a game-changer for above-ground pool owners in high-wind regions, but it is not compatible with in-ground pools, which lack an exposed outer wall to wrap.

Off-Season Pool Care Tasks to Prevent Damage

Winterizing your pool is not a one-and-done chore that you can forget about until spring. Throughout the winter, heavy winds can shift covers, and accumulated snow can strain the structural integrity of your pool walls. Regularly inspect the pool cover tension, checking that cables remain tight and water tubes are properly positioned to prevent the cover from slipping into the pool.

Additionally, keep an eye on water accumulation on top of solid covers, as heavy puddles must be pumped off immediately. Excess weight from standing water can put immense stress on above-ground pool walls and structural frames. Checking these elements once a month, especially after major winter storms, protects your investment and ensures a stress-free spring opening.

Check the pool chemistry under the cover if the winter is unseasonably warm. Algae can begin to grow if temperatures rise above 60°F, even if the pool is covered. Pulling back a corner of the cover to test the water in early spring allows you to add a touch-up dose of algaecide before problems start.

Conclusion

Closing your pool with high-quality winterization gear is the single best way to protect your backyard investment from the destructive power of winter freezes. Taking the time to prep your water, blow out plumbing lines, and secure a durable cover pays massive dividends when warm weather returns. With these nine essential supplies in your tool kit, you can rest easy knowing your pool is safe, secure, and ready for an easy spring opening.