10 Essential Steps and Gear for Winterizing Your Inground Pool

As autumn leaves begin to fall and the summer heat fades, the clock starts ticking on your pool care calendar. Skipping or rushing the winterization process can lead to cracked pipes, ruined liners, and a green nightmare come spring. Securing the right gear now ensures your inground pool survives the harshest freeze and opens crystal clear next season.

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Preparing Your Inground Pool for Freezing Temperatures

Closing an inground pool is a systematic battle against physics. When water freezes, it expands by about nine percent, exerting immense pressure that easily cracks PVC pipes, splits concrete, and ruins filtration systems. Successful winterization is about removing water from where it shouldn’t be and stabilizing the water that remains.

The process begins about a week before the actual closing day with a deep clean and chemical adjustment. Vacuuming debris and balancing the pH, alkalinity, and calcium hardness ensures your winter chemicals work with maximum efficiency. If algae is present, it must be completely eradicated before the cover goes on, or it will fester under the winter sun.

Once clean, the pool water level must be lowered below the skimmer mouth—typically about three to six inches for mesh covers, or just below the tile line for solid covers. This crucial step prevents water from entering the skimmer throat where freezing temperatures can easily crack the plastic housing.

Winter Chemical Kit – In The Swim Ultimate Closing Kit

Leaving pool water untreated for six months is an open invitation for algae blooms and staining. A winter chemical kit keeps the water chemistry stable, prevents mineral deposits from scaling the walls, and ensures the water remains clear until spring. Without these slow-dissolving agents, opening the pool becomes a costly, multi-week scrubbing marathon.

The In The Swim Ultimate Closing Kit is a smart choice because it eliminates the guesswork of chemical dosing. It contains a highly concentrated winterizer, a metal-free stain preventer, and a non-chlorine shock that won’t bleach pool liners. The standout feature is the time-released winter chemical dispenser, which continuously dispenses sanitizer long after the initial treatment dissipates.

• Compatibility: Works with chlorine, saltwater, and bromine pools
• Capacity Options: Kits available for pools up to 10,000, 22,000, or 35,000 gallons
• Included Components: Winterizer liquid, pool shock, stain remover, and a slow-release floater

Before tossing the dispenser in, make sure the pool water is thoroughly circulated for at least four to six hours after adding the liquid chemicals. This kit is ideal for pool owners who want a straightforward, pre-measured chemical regimen. It is not suitable for pools that already have active, heavy algae blooms, which must be killed with standard liquid chlorine before the kit is applied.

Pool Brush – Lalapool Heavy Duty Wall Brush

Before any chemicals are added or covers are secured, every square inch of the pool wall and floor must be brushed. Microscopic algae spores and calcium scale cling to pool surfaces, hiding in tiny pores where chemicals cannot easily penetrate. A thorough brushing forces these contaminants into suspension so the filtration system can catch them before shutoff.

The Lalapool Heavy Duty Wall Brush stands out because of its extra-wide 18-inch profile and heavy-duty aluminum reinforced back. This rigid construction prevents the brush from flexing or snapping when you apply downward leverage in the deep end. The curved ends are designed to glide smoothly into tight corners and step transitions without scratching the finish.

• Width: 18 inches
• Backing Material: Cast aluminum for maximum rigidity
• Bristle Material: Poly-nylon bristles compatible with concrete, plaster, and vinyl pools

Keep in mind that this brush head requires a standard telescopic pool pole, which is sold separately. While the bristles are tough enough for stubborn plaster scale, user care should be taken on older, weathered vinyl liners to avoid tears. This brush is perfect for anyone needing maximum leverage to scrub a seasonal layer of grime, but it is overkill for daily light dusting of small fiberglass spas.

Pool Cover Pump – Little Giant APCP-1700 Automatic Pump

Rain, melting snow, and ice accumulation can weigh thousands of pounds, turning a taut solid safety cover into a dangerous, sagging basin. This weight damages cover springs, stretches anchors out of deck concrete, and can drag the entire cover into the pool. A dependable cover pump removes this water automatically, preserving the structural integrity of your cover system.

The Little Giant APCP-1700 Automatic Pump is an industry workhorse for off-season water management. It features a built-in float switch that automatically activates the pump when water reaches two inches and shuts off when it drops to half an inch. With a flow rate of 1,700 gallons per hour, it clears heavy downpours quickly before the water can freeze into a solid sheet.

• Flow Rate: 1,700 gallons per hour
• Activation: Automatic mechanical float switch (no manual monitoring needed)
• Discharge Connection: Standard 3/4-inch garden hose thread

Ensure the pump is placed on a level section of the cover, and clear away large leaves that might clog the intake screen. It requires a continuous power source, so a heavy-duty, weather-rated extension cord routed to a GFCI outlet is mandatory. This pump is a necessity for anyone using solid or hybrid safety covers, though it is unnecessary for those with high-drainage mesh covers that do not collect standing water.

Safety Pool Cover – Water Warden Rectangle Safety Cover

A winter cover is the primary line of defense against the elements, stray animals, and curious children during the dark winter months. Standard tarp covers held down by water bags are prone to tearing and wind damage, often collapsing under snow loads. A tension-secured safety cover acts like a trampoline, keeping debris out while safely supporting heavy weights.

The Water Warden Rectangle Safety Cover utilizes high-density, lightweight mesh that filters out fine debris while letting water drain through. The straps feature double-pack webbing with a break strength of over 4,000 pounds, supported by heavy-duty stainless steel springs and flush-mount brass anchors. This design prevents water from pooling on top, eliminating the need for a pump while keeping the yard looking clean.

• Material: Lightweight, UV-resistant polypropylene mesh
• Hardware: Brass anchors, stainless steel springs, installation tool included
• Safety Rating: Meets ASTM F1346-91 safety standards

Installing this cover requires drilling holes into the concrete deck with a rotary hammer drill, which carries a minor learning curve for DIYers. It is critical to order the exact size of your pool casing, adding the recommended overlap margin (typically two feet wider and longer than the pool dimensions). This cover is ideal for families seeking maximum safety and durability, but it is not recommended for irregularly shaped pools unless custom-ordered.

Line Blower – Cyclone Pro 3 HP Line Blower

Water trapped inside underground PVC pipes will freeze, expand, and shatter the lines, leading to catastrophic leaks that cost thousands of dollars to excavate and repair. A standard shop vac lacks the volume and static pressure needed to push water out of deep main drains and long plumbing runs. A dedicated line blower creates a massive volume of air to clear every drop of water from the lines.

The Cyclone Pro 3 HP Line Blower is engineered specifically for the extreme backpressure of pool plumbing systems. Its powerful 3 horsepower bypass motor delivers up to 130 CFM of airflow, which easily evacuates water from 2-inch pipes and deep-water main drains. The rugged plastic housing is built to survive damp pool sheds and rough concrete decks without denting or rusting.

• Motor: 3.0 HP, 120-volt bypass motor
• Airflow Capacity: 130 CFM (Cubic Feet per Minute)
• Portability: Integrated carry handle with a compact, impact-resistant body

Using this blower requires a basic understanding of your pool’s manifold valves to ensure air is directed to one line at a time. Always use a dedicated pool blow-out hose and secure fittings to prevent high-pressure air lines from whipping or blowing off. This tool is a must-have for DIY pool owners who want to avoid paying a pool company every autumn, but it is unnecessary for warm-climate pool owners who do not experience hard freezes.

Winter Expansion Plug – Swimline Rubber Expansion Plug

Once the plumbing lines are blown clear of water, they must be immediately sealed to prevent pool water from backflowing into the pipes. A failure to seal these lines properly renders the entire blowout process useless, leaving the plumbing vulnerable to ice expansion. High-quality expansion plugs wedge tightly into return lines, creating an airtight, watertight barrier.

The Swimline Rubber Expansion Plug features a tapered rubber body that compresses evenly inside the pipe wall when the wing nut is tightened. Unlike cheap plastic plugs that crack under freezing conditions, these use heavy-duty stainless steel bolts and wing nuts that resist corrosion in wet environments. The ribbed rubber design ensures a positive seal that won’t slip out under backpressure from the empty lines.

• Material: Industrial-grade rubber with stainless steel hardware
• Sizing Options: Available in standard sizes from #0 to #14 to fit 1.5-inch and 2-inch lines
• Application: Ideal for return inlets, cleaner lines, and skimmer bottoms

It is critical to measure your return line diameters precisely before purchasing, as a plug that is too small will blow out under pressure, and one too large will not insert deeply enough to seal. Ensure the rubber is clean and free of pool chemical residue before insertion to prevent slippage. This plug is essential for any pool owner winterizing an inground system in freezing climates, while thread-in style plugs remain better suited for pools with clean, threaded female fittings.

Skimmer Guard – Gizzmo Ultra Skimmer Freeze Protection

The skimmer is one of the most vulnerable parts of an inground pool because water naturally collects in its throat, where it is exposed to freezing air on multiple sides. If water freezes inside the skimmer, it will crack the plastic housing, necessitating a destructive and expensive deck excavation to replace. A skimmer guard acts as a sacrificial compression chamber, collapsing inward to absorb ice expansion.

The Gizzmo Ultra Skimmer Freeze Protection device is a hollow, heavy-duty plastic tube that threads directly into the bottom of the skimmer. It stands 12 inches tall and is designed to deform under the crushing pressure of expanding ice, shielding the delicate skimmer walls. The integrated 1.5-inch and 2-inch threads make it highly versatile, allowing it to seal the pipe opening while simultaneously protecting the skimmer body.

• Height: 12 inches (designed for deep skimmers)
• Threads: Dual 1.5-inch and 2-inch tapered threads
• Material: High-density, crushable polyethylene plastic

For a reliable, watertight seal, always wrap the Gizzmo’s plastic threads with a few layers of Teflon tape before screwing it into the skimmer bottom. Make sure to choose the “Ultra” version if you have deep, modern skimmers, as the standard version may not sit high enough to protect the throat. This is a critical investment for any pool owner with a standard skimmer system in freezing zones, but it is not compatible with specialized suction ports or non-threaded skimmer wells.

Pool Antifreeze – Splash RV & Marine Antifreeze

Even after blowing out the plumbing lines, small pockets of condensation or residual water can pool in low spots or elbows of your underground pipes. If this trapped water freezes, it can cause hairline fractures that go unnoticed until your water bill spikes the following summer. Adding specialized pool antifreeze to the plumbing lines provides an extra layer of insurance against sub-zero temperatures.

Splash RV & Marine Antifreeze is formulated with high-purity propylene glycol, providing burst protection down to -50°F. Unlike toxic automotive antifreeze, this formula is completely non-toxic and biodegradable, ensuring it won’t harm swimmers, pets, or the pool filtration system when flushed out in the spring. It is pre-diluted and ready to pour directly into skimmers, return lines, and pump housings.

• Base Material: Non-toxic propylene glycol (safe for pool components)
• Temperature Rating: Burst protection down to -50°F (-46°C)
• Formula: Ready-to-use, non-staining formula

Never use automotive ethylene glycol antifreeze in a pool, as it is highly toxic to humans and pets and will permanently damage vinyl pool liners. When pouring the antifreeze down the plumbing lines, ensure you have plugged the pool side of the pipe first so the liquid stays concentrated inside the underground run. This is highly recommended for cold-climate pool owners with complex plumbing setups, but it is unnecessary in regions that only experience brief, light frosts.

Pool Air Pillow – Poolmate Heavy Duty Air Pillow

When ice forms across the surface of an inground pool, it exerts immense outward pressure against the pool walls and tile line. A pool air pillow floats in the center of the pool under the winter cover, creating an artificial low-pressure void in the ice sheet. As the surrounding ice expands, it pushes inward against the compressible pillow rather than outward against your expensive pool structure.

The Poolmate Heavy Duty Air Pillow is built from 16-gauge vinyl, making it exceptionally resistant to punctures and cold-weather cracking. It measures 4×4 feet, providing a substantial expansion buffer that is ideal for mid-sized to large inground pools. The double-reinforced seams are designed to withstand the crushing force of shifting ice sheets without bursting.

• Dimensions: 4 x 4 feet
• Material: 16-gauge heavy-duty vinyl
• Valves: Easy-inflation speed valve with a leak-proof seal

The most common mistake when using an air pillow is inflating it to 100 percent capacity; instead, inflate it to only 60 to 80 percent to leave room for compression. Use nylon ropes anchored to opposite sides of the pool deck to keep the pillow centered, preventing it from drifting to the edges where it cannot protect the walls. This is a critical safety item for pools utilizing solid winter covers, but it is generally unnecessary for mesh safety covers that allow water and snow to pass through freely.

Pool Leaf Net – Blue Wave Leaf Net Cover

Deciduous trees shed tons of leaves and organic debris directly onto pool covers every autumn, creating a heavy, rotting mess. If left to decompose, these leaves turn standing rainwater into a tea-colored sludge that is heavy to pump off and can stain your winter cover. A dedicated leaf net sits on top of your winter cover, catching all falling debris for quick and effortless removal.

The Blue Wave Leaf Net Cover is constructed from a durable, woven polyethylene mesh that allows water to pass through while trapping the smallest leaves and twigs. It features a generous 4-foot overlap to ensure complete coverage over the edges of your primary winter cover. The package includes a heavy-duty, vinyl-coated steel cable and a metal ratchet tightener to secure it firmly against autumn winds.

• Material: Woven, UV-protected polyethylene mesh
• Overlap: 4-foot extra material margin for a secure fit
• Included Accessories: Vinyl-coated steel cable and brass-plated winch

To get the most out of this net, it must be installed immediately after the primary cover goes on and removed before the first major snow or hard freeze. If left on during a freeze, the wet leaves will freeze solid to the primary cover, making removal impossible and risking damage to the net. This net is a game-changer for pools surrounded by oak, maple, or pine trees, but it is redundant for pools in open, tree-free landscapes.

Off-Season Maintenance Tips to Protect Your Investment

Winterizing your pool is not a “set-it-and-forget-it” task; active off-season maintenance is essential to prevent costly surprises in the spring. Throughout the winter, periodically check the tension on your safety cover straps to ensure they have not sagged under snow loads. If you use a solid cover, ensure the cover pump is free of leaves and operating correctly after heavy rain or snowmelt.

Keep an eye on the water level beneath the cover, especially during mid-winter thaws. If the water level drops significantly due to a slow leak, the safety cover will lose its bottom support, putting excessive stress on the deck anchors and risking cover collapse. Conversely, if the water rises too high, it can touch the underside of a solid cover, freezing to it and causing damage.

Finally, when heavy snowstorms strike, use a long-handled, soft-bristled broom to gently clear excessive snow accumulation off the cover. Never use a metal shovel or a hard rake, which can easily puncture the cover material. Taking these small, proactive steps ensures your equipment remains protected and makes spring re-opening a breeze.

Investing in high-quality winterizing gear and following a systematic closing process is the best insurance policy for your backyard investment. By taking the time to blow out the lines, balance the chemicals, and secure a heavy-duty cover, you protect your pool from catastrophic freeze damage. When the warm weather returns, you will reap the rewards of your hard work with a crystal-clear pool that is ready for summer fun.