10 Essential Pool Closing Supplies for Freezing Winter Temperatures

Watching the first autumn leaves drift onto a cold pool surface is the ultimate reminder that freezing temperatures are just around the corner. Neglecting proper winterization now means risking cracked pipes, ruined liners, and thousands of dollars in spring repair bills. Equipping yourself with the right seasonal gear ensures your backyard oasis survives the harshest winter freeze completely unscathed.

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Why Deep Freeze Prep Matters for Your Pool

Water expands by approximately nine percent when it freezes, exerting immense pressure on whatever contains it. In a swimming pool, this expansion can easily crack heavy-duty PVC underground pipes, shatter plastic skimmer wells, and tear vinyl liners. Once the ground freezes, the surrounding soil shifts, compounding the stress on your pool’s structural shell and plumbing system.

Proper deep-freeze preparation is not about keeping the water clean; it is about mitigating these destructive physical forces. It requires completely clearing water from vulnerable plumbing lines, sealing off entry points, and chemically balancing the dormant water. Spending a few focused hours in the fall saves weeks of frustration and massive financial headaches when the spring thaw arrives.

Winter Cover – Loop-Loc Safety Pool Cover

A high-quality winter cover does more than keep leaves out of the water; it acts as a structural shield against heavy snow loads and prevents tragic backyard accidents. Standard tarp covers often sag, collect dangerous puddles of meltwater, and tear under the weight of winter storms. A tensioned safety cover keeps the barrier taut, clean, and secure throughout the coldest months of the year.

The Loop-Loc Safety Pool Cover stands out because of its legendary burst strength and ultra-durable mesh construction. Made with double-mercerized black polypropylene thread, this cover allows rain and melting snow to drain through while blocking fine debris and blocking out algae-promoting sunlight. Its heavy-duty brass anchors countersink flush into your deck when not in use, providing a clean look and a trip-free surface during the swimming season.

• Compatible with: In-ground concrete, vinyl liner, and fiberglass pools
• Material: Ultra-strength double-mercerized polypropylene mesh
• Weight capacity: Engineered to support up to 4,000 lbs of tensioned load

Installing this cover requires some initial effort, as it involves drilling anchor holes into concrete, wood, or stone decking using a rotary hammer drill. Once the initial layout is established, however, putting the cover on and taking it off each season takes less than thirty minutes with the included installation tool.

This premium safety cover is ideal for in-ground pool owners who prioritize safety, longevity, and a clean winter aesthetic. It is not the right fit for above-ground pool owners or those looking for a cheap, temporary tarp solution for a single season.

Cover Pump – Wayne WAPC250 Pool Cover Pump

Accumulated water from heavy rain and melting snow can quickly weigh down a pool cover, straining the anchors and risking a catastrophic structural failure. A reliable cover pump automatically removes this pooling water before it freezes into a massive, heavy sheet of ice. This prevents the cover from sinking into the pool and pulling the deck anchors or pool walls with it.

The Wayne WAPC250 Pool Cover Pump is the industry standard because of its smart, oil-free automatic sensing technology. It automatically turns on when water levels reach 2.1 inches and shuts off when the surface is cleared down to 0.75 inches, meaning you do not have to brave freezing rain to plug it in. Its built-in strain protection prevents debris from clogging the intake, while the high-flow design pumps up to 3,000 gallons per hour.

• Flow rate: Up to 3,000 gallons per hour
• Activation level: Turns on at 2.1 inches of water; turns off at 0.75 inches
• Power source: 120V AC with 25-foot power cord

Before buying, ensure you have a heavy-duty, outdoor-rated extension cord long enough to reach your pool’s center. While the pump features automatic freeze protection to prevent motor damage, it should be removed from the cover during prolonged deep freezes when standing water turns completely solid.

This pump is a must-have for anyone using solid winter covers or solid-center safety covers where water naturally pools. It is unnecessary for free-draining mesh safety covers, unless local winter conditions cause heavy slush buildup that blocks natural drainage.

Winterizing Kit – InTheSwim Deluxe Pool Kit

Leaving pool water untreated for six months invites a nightmare of black algae, organic staining, and mineral scaling. A dedicated winterizing kit provides a sustained chemical defense system that remains active even under a solid cover. This ensures that when you pull the cover off in the spring, you are greeted by clear water rather than a swampy green mess.

The InTheSwim Deluxe Pool Kit contains a perfectly balanced selection of winterizing chemicals designed to work together without degrading your pool liner. The kit features a powerful winter shock, a slow-releasing winterizer chemical dispenser, a metal stain preventer, and a unique winter floater that constantly dispenses non-chlorine sanitizer. This multi-stage defense targets algae spores and mineral buildup even when the water temperature drops below freezing.

• Pool compatibility: Chlorine and salt-water systems up to 30,000 gallons
• Included treatments: Winterizer, winter shock, metal stain preventer, slow-release dispenser
• Active period: Protects up to 6 months of off-season closure

When using this kit, always match the kit size to your pool’s actual gallon capacity, rounding up if you are close to the limit. For the best results, distribute the chemicals evenly across the pool with the pump running for at least four hours before lowering your water level for the winter.

This kit is perfect for pool owners who want a straightforward, pre-measured chemical regimen that guarantees easy spring openings. It is not ideal for those with custom salt systems or specialized plaster finishes that require highly customized chemical balances.

Pool Air Pillow – Robelle Ice Equalizer

As water freezes in an above-ground pool, it expands outward, placing immense lateral pressure on the pool walls and liner. An air pillow sits in the center of the pool under the cover, acting as an expansion cushion that absorbs this inward pressure. When ice forms, it expands inward against the compressible pillow rather than outward against the rigid pool structure.

The Robelle Ice Equalizer is built from heavy-duty 16-gauge vinyl, making it significantly more puncture-resistant than cheap, single-season alternatives. It features a secure, leak-proof valve design and reinforced grommet corners that allow you to tie it securely in the exact center of your pool. This ensures the pillow stays put even when subjected to shifting ice and high winter winds.

• Material thickness: Heavy-duty 16-gauge vinyl
• Compatible uses: Above-ground pools and solid-covered in-ground pools
• Size options: Available in 4′ x 4′, 4′ x 5′, and 4′ x 8′ dimensions

The most common mistake is inflating the pillow to its maximum capacity, which causes it to pop under the weight of snow and ice. Only inflate the pillow to 60% to 70% capacity to allow plenty of room for compression when the freeze sets in.

This is an absolute necessity for any above-ground pool owner looking to protect their walls from buckling over the winter. It is generally not needed for in-ground pools using tightly tensioned mesh safety covers.

Skimmer Guard – Gizzmo Ultra Freeze Plug

The skimmer is one of the most vulnerable parts of an in-ground pool during a deep freeze. Water naturally accumulates in the skimmer throat, and when it freezes, the expanding ice can easily crack the surrounding plastic housing, leading to leaks that require excavation to repair. A skimmer guard acts as a sacrificial expansion chamber, collapsing under the pressure of freezing water to save the skimmer itself.

The Gizzmo Ultra Freeze Plug features a clever, hollow, heavy-duty plastic design that screws directly into the bottom threads of the skimmer. It seals off the plumbing line below while providing a 16-inch-long collapsible cylinder that safely absorbs the crushing force of ice inside the skimmer bucket. This dual-action design protects both your underground pipes and the delicate skimmer housing in one simple step.

• Thread sizes: 1.5-inch and 2-inch options
• Compatible uses: Standard in-ground skimmer wells
• Body length: 16 inches of freeze-absorption clearance

Before buying, verify whether your skimmer plumbing requires the 1.5-inch or 2-inch threaded version of the Gizzmo. Apply a few wraps of Teflon tape to the threads to ensure an airtight seal, and never over-tighten it, as plastic threads can strip under too much torque.

This is a crucial protective tool for in-ground pool owners in regions that experience deep, ground-penetrating freezes. It is not suitable for above-ground pool skimmers, which are typically disconnected and drained entirely.

Expansion Plug – Anderson Winterizing Plug

After blowing all the water out of your pool’s returns and cleaner lines, you must seal those openings to prevent water from creeping back in. If water re-enters the pipes and freezes, it will split the PVC underground, turning your spring opening into a major plumbing excavation project. Expanding rubber plugs provide a dependable, airtight seal that withstands freezing temperatures and shifting ice.

The Anderson Winterizing Plug is constructed with commercial-grade, chemical-resistant rubber and heavy-duty stainless steel bolts. The non-corrosive nylon wing nuts allow you to easily tighten the plugs by hand, expanding the rubber to form a perfect, high-pressure seal inside the pipe. Unlike cheap plastic plugs, these rubber expansion plugs do not crack, shrink, or degrade when exposed to freezing water and harsh winter chemicals.

• Compatible pipe sizes: Fits standard 1.5-inch and 2-inch plumbing lines
• Material: Non-slip industrial rubber with stainless steel bolts and nylon wing nuts
• Best for: Return jets, cleaner lines, and skimmer winterization

You must measure your return jet fittings precisely before ordering, as pool lines typically range from 1.5 inches to 2 inches in diameter. Clean any algae or debris out of the pipe opening before inserting the plug to ensure the rubber makes a continuous, leak-free seal against the PVC wall.

These plugs are indispensable for any in-ground pool owner who blows out their lines for the winter. They are not necessary for pools located in warm climates where water lines are never drained or blown out.

Pool Antifreeze – Splash Non-Toxic Antifreeze

Even after a thorough blowout, small pockets of water can pool in low points of underground PVC lines. When temperatures drop below zero, this residual moisture freezes, expands, and splits the pipes. Adding a specialized pool antifreeze to the lines provides an extra layer of insurance by lowering the freezing point of any remaining water.

Splash Non-Toxic Antifreeze is formulated specifically for pool plumbing, utilizing a propylene glycol base that is completely non-toxic to humans and pets. It provides burst protection down to -50°F, ensuring your pipes remain safe during the most extreme winter cold snaps. Unlike automotive antifreeze, it is safe to discharge into the pool water during spring opening and will not damage vinyl liners or fiberglass shells.

• Freeze protection limit: Down to -50°F burst protection
• Formulation: Non-toxic propylene glycol (biodegradable)
• Compatible plumbing: PVC, flexible hoses, and copper pool lines

Never dilute this product before pouring it into your lines, as doing so raises its freezing point and compromises its protective qualities. Use a funnel to pour one gallon of antifreeze directly into each line after blowing it out, then quickly seal the line with an expansion plug.

This is highly recommended for in-ground pool owners in northern climates who want foolproof protection for underground plumbing. Do not use this if you have an above-ground pool with removable hoses that can simply be stored in a warm garage.

Cover Seal Wrap – Gladon Winter Cover Seal

High winter winds are the natural enemy of above-ground pool covers. Once wind gets underneath the edge of a cover, it acts like a sail, whipping the material, loosening the cables, and eventually tearing the cover completely off the pool. Wrapping the perimeter of the pool seals this gap, keeping the cover locked flat against the outer wall.

Gladon Winter Cover Seal is a specialized, high-stretch poly-film wrap designed specifically to withstand harsh outdoor winter conditions. It is formulated with unique UV inhibitors to prevent it from degrading under constant winter sunlight, and it clings tightly to itself without leaving sticky adhesive residue on your pool’s metal walls. Wrapping this around the top ledge of your pool creates an airtight barrier that completely eliminates wind lift.

• Compatible pool types: Above-ground round and oval pools
• Material: High-tensile UV-resistant stretch film
• Roll dimensions: 80 feet, 150 feet, and 500 feet lengths

For maximum security, wrap the perimeter of your pool at least three to four times, applying firm tension as you go. Focus on the area directly under the top rail where wind is most likely to find a gap and lift the cover.

This wrap is an essential accessory for above-ground pool owners who live in wide-open or high-wind regions. It is entirely unnecessary for in-ground pools or pools protected by heavy safety covers.

Line Blower – Cyclone Pro Line Blowout Vacuum

Using a standard shop vacuum to blow out pool lines is one of the most common DIY winterizing mistakes. Shop vacs lack the backpressure required to push water out of deep main drains or long, winding return lines, leaving water behind to freeze and crack the pipes. A dedicated line blower delivers the concentrated high-volume airflow needed to clear plumbing lines completely.

The Cyclone Pro Line Blowout Vacuum is the undisputed champion of line clearing, featuring a powerful 3.0 HP bypass motor designed specifically for pool winterization. It generates up to 130 CFM of airflow at a high pressure that easily clears lines up to ten feet deep. Its rugged, impact-resistant plastic housing is built to survive the bumps and drops of a busy outdoor workday.

• Motor rating: 3.0 HP bypass motor
• Airflow performance: 130 CFM at high backpressure
• Electrical draw: 14 amps (requires a dedicated 15A/20A GFCI circuit)

Because this motor draws a significant amount of electricity, you should plug it directly into a dedicated 15-amp or 20-amp GFCI outlet to avoid tripping breakers. It comes with a flexible hose and a stepped adapter, but you may need specific threaded fittings to connect it directly to your skimmer or pump basket.

This is a premium, heavy-duty tool for DIY-minded in-ground pool owners who want professional-grade blowout results year after year. It is overkill for small above-ground pools with simple, short plumbing runs.

Water Tube – Robelle Double Chamber Water Bag

Traditional solid tarp covers for in-ground pools require weight around the perimeter to keep them from sliding into the water or blowing away in the wind. Standard concrete blocks or bricks should never be used, as they can tear the cover and damage your pool deck if shifted by ice. Water tubes provide a soft, heavy, and secure anchor that conforms perfectly to the deck surface.

The Robelle Double Chamber Water Bag is constructed from heavy-duty 18-gauge vinyl that resists punctures, tears, and UV degradation. Its double-chamber design is a crucial safety feature: it prevents the bag from rolling on sloped decks, and if one chamber gets punctured by a sharp twig, the other chamber remains intact to keep the cover anchored. The leak-resistant valves are designed to stay sealed even when the water inside freezes solid.

• Material thickness: 18-gauge heavy-duty vinyl
• Compatible uses: In-ground solid tarp covers
• Lengths available: 8-foot and 10-foot options

When filling these water tubes, only fill them to 50% to 75% capacity to allow space for the water to expand as it turns to ice. Overfilled bags will split along the seams when frozen, rendering them useless halfway through the winter season.

These water tubes are essential for in-ground pool owners utilizing a standard solid winter tarp cover. They are completely unnecessary if you have an anchored safety cover or an above-ground pool.

How to Safely Blow Out and Plug Your Pool Lines

Successfully winterizing your pool lines is a precise, step-by-step process that must be done in the correct sequence to prevent water from re-entering the plumbing. Begin by lowering the pool’s water level below the skimmer mouth, typically about four to six inches below for a mesh safety cover. Next, hook up your line blower to the skimmer or the pool pump basket, ensuring all other valves on your manifold are closed to concentrate the air pressure where you need it.

Turn on the blower and start by clearing the skimmer line first, plugging it with a Gizzmo once it is completely clear of water. Move on to the return lines, blowing them out one by one starting with the line closest to the pump and working your way to the furthest return. As each line begins blowing pure air and mist, pour in your non-toxic antifreeze, quickly insert your rubber expansion plug, and tighten the wing nut until it is secure.

The main drain at the bottom of the pool requires a specific technique known as “air locking.” Blow air through the main drain line until you see a steady stream of large bubbles erupting from the bottom of the pool. Once the line is clear, quickly close the main drain valve at your pump manifold to trap the air inside the pipe; this pressurized air pocket acts as a barrier, preventing water from rising back up into the line where it could freeze.

Conclusion

Investing in high-quality winterization gear is the single best way to protect your backyard pool investment from freezing temperatures. By taking the time to thoroughly blow out your lines, balance your water, and secure a heavy-duty cover, you ensure a hassle-free spring opening. When the warm weather finally returns, your pool will be ready to dive back into without any expensive surprises.