8 Essential Pool Closing Checklist Items for a Backyard Pool

As the autumn leaves start to fall, the time comes to transition your backyard pool from a summer oasis into winter hibernation. Neglecting this seasonal ritual or rushing through it with cheap, substandard gear is a recipe for cracked pipes, ruined liners, and a green swamp come spring. Equipping yourself with the right tools ensures your investment survives the freeze-thaw cycle intact and ready for another warm season.

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Why Prep Work Prevents Costly Spring Repairs

Proper winter preparation is essentially insurance for your backyard investment. When water freezes, it expands by roughly nine percent, exerting immense outward pressure on everything containing it. Without the proper prep work, this expansion easily cracks underground PVC pipes, splits pump housings, and shatters skimmer assemblies.

Furthermore, closing a pool with unbalanced water allows algae spores to feast during the milder shoulder months of autumn and spring. A neglected pool will require days of heavy chemical scrubbing and massive water changes to clear up. Spending a little extra effort and using the right equipment in the fall saves thousands of dollars in structural repairs and chemical treatments when the weather warms up.

Establishing a methodical closing routine is the secret to stress-free pool ownership. This means systematically treating the water, clearing the plumbing, protecting the structural weak points, and securing a reliable barrier over the pool. Skipping any of these steps creates a weak link that winter weather will inevitably exploit.

Winterizing Kit – In The Swim Deluxe Pool Kit

Winterizing kits deliver a pre-measured chemical defense system to keep your pool water clear, balanced, and algae-free during the long off-season. Rather than guessing at chemical ratios, these kits bundle everything needed to prevent stain formation, scale buildup, and organic growth. They slowly release active ingredients over several months, ensuring the water remains stable even when the filtration system is turned off.

The In The Swim Deluxe Pool Kit stands out because of its highly concentrated, commercial-grade formulas that do not bleach vinyl liners. The kit features a time-released winterizer floater filled with non-chlorine oxidizing agent, a powerful winter stain away compound, and an exceptionally strong winter algaecide. These components work in tandem to eliminate organic contaminants without degrading your pool surfaces or cover materials.

Before tossing this kit into the pool, ensure the water chemistry is already balanced and the pool is thoroughly vacuumed. You must run the pool filter for at least several hours after adding the liquid chemicals to distribute them evenly before lowering the water level. * Best for: In-ground and above-ground pool owners who want a straightforward, all-in-one chemical regimen for pools up to 20,000 gallons. * Not ideal for: Ultra-small splash pools or massive residential pools over 35,000 gallons, which require multiple kits or customized chemical dosing.

Safety Cover – Loop-Loc Mesh Safety Cover

A safety cover acts as an impenetrable shield for your pool, preventing leaves, debris, and winter precipitation from entering the water. Unlike cheap tarp covers held down by water bags, a safety cover is anchored directly into the pool deck, creating a taut surface that can support substantial weight. This prevents accidental drowning incidents and keeps heavy winter winds from ripping the cover away.

The Loop-Loc Mesh Safety Cover is widely considered the gold standard in pool protection due to its ultra-strong, double-perimeter webbing and heavy-duty brass anchors. The dense mesh material allows rain and melting snow to drain through into the pool while filtering out fine debris, preventing dangerous water accumulation on top of the cover. It boasts a high break strength, meaning it can easily support the weight of wandering pets, wild animals, or children who might step onto it.

Installing a safety cover for the first time requires drilling anchor holes into your concrete, stone, or wood deck using a rotary hammer drill. Precision is critical during this initial layout, as any misaligned anchors will cause uneven tension and premature wear on the fabric. * Best for: Pool owners with children or pets who prioritize safety, durability, and a clean backyard aesthetic over the winter. * Not ideal for: Above-ground pools without surrounding decks, or budget-focused owners looking for a quick, tool-free installation.

Pool Air Pillow – Robelle Ice Equalizer

An air pillow is a critical buffer for above-ground pools, sitting in the center of the pool beneath the winter cover to absorb the expansion force of freezing water. As ice forms on the surface, it naturally expands outward toward the delicate pool walls. The air pillow compresses under this lateral pressure, relieving strain on the pool structure and preventing the walls from buckling or splitting.

The Robelle Ice Equalizer is built from heavy-duty, puncture-resistant 16-gauge vinyl, making it far tougher than standard retail-grade pillows. It features a reliable leak-proof valve that holds air throughout the sub-zero winter temperatures without deflating. The rugged exterior is designed to withstand the abrasive sliding of a heavy winter cover as ice and snow accumulate on top.

A common mistake is inflating the air pillow completely to its maximum capacity. You should only inflate the pillow to 60% to 80% capacity to allow room for compression when ice presses against it. Additionally, you will need to tie ropes to the corner grommets to anchor the pillow securely in the exact center of the pool. * Best for: Above-ground pool owners in cold climates who experience prolonged, hard freezing conditions. * Not ideal for: In-ground pools, where safety covers are used and lateral wall pressure from ice is not a primary structural concern.

Skimmer Guard – Gizzmo Skimmer Expansion Plug

The skimmer is one of the most vulnerable parts of an in-ground pool during freezing weather. Water left inside the skimmer throat will freeze, expand, and crack the plastic housing, leading to a massive, expensive underground leak. A skimmer guard screws directly into the bottom of the skimmer to seal the plumbing line and absorb ice expansion inside the skimmer well.

The Gizzmo Skimmer Expansion Plug is a heavy-duty, hollow plastic tube engineered to collapse under the pressure of freezing water. If ice forms inside the skimmer, the Gizzmo crushes inward to absorb the force, protecting the delicate skimmer walls from cracking. It features standard male threads at the bottom, allowing it to seal the pipe leading to the pump while simultaneously acting as a freeze buffer.

Before installing the Gizzmo, wrap the threads with teflon tape to ensure an airtight seal in the plumbing line. It is crucial to choose the correct size, as most skimmers require either a 1.5-inch or 2-inch thread size to seat properly. * Best for: In-ground pool owners living in cold regions who want simple, reliable protection for their skimmer housing. * Not ideal for: Pools with non-threaded skimmer lines, or pools located in climates that never experience freezing temperatures.

Winter Plug – Anderson Pool Rubber Expansion Plug

Winter plugs are used to seal the pool’s return lines, cleaner lines, and main drains after the water has been blown out of the plumbing. By creating a physical, airtight barrier inside the pipe openings, these plugs prevent pool water from seeping back into the empty lines. If water re-enters the plumbing and freezes, it will split the underground PVC pipes, requiring costly excavation to repair.

The Anderson Pool Rubber Expansion Plug features a robust, marine-grade rubber body and a corrosion-resistant stainless steel wing nut. Tightening the wing nut compresses the rubber vertically, forcing it to expand horizontally against the inside of the pipe for a perfect, airtight seal. The heavy-duty construction ensures the plug will not dry rot, crack, or slip out under pressure from lingering moisture or air locks.

Always measure the inner diameter of your return lines before purchasing, as plugs are sized by specific numbers (such as #9 or #10) to match different pipe dimensions. Lubricating the rubber slightly with a pool-safe silicone lubricant can help slide the plug deep into the fitting for a secure hold. * Best for: Anyone DIY-closing an in-ground pool who needs a guaranteed, heavy-duty seal for their plumbing returns. * Not ideal for: Pools with threaded returns that require threaded cap-style plugs instead of expansion plugs.

How to Properly Blow Out and Seal Pool Lines

Clearing the water from your pool lines is the most critical step in prevent winter freeze damage. To begin, lower the pool water level to about three to six inches below the skimmer mouth. Connect your line blower to the skimmer plumbing line or the pump basket intake, ensuring all other valves on your manifold are closed to isolate the line you are working on.

Turn on the blower and watch the return lines inside the pool; you will see a massive rush of water followed by a steady stream of air bubbles. Once the line is blowing pure air with no water sputtering, quickly slide a rubber expansion plug into the return fitting and tighten the wing nut securely. This creates an airtight seal while the line is under positive pressure, preventing any water from creeping back inside.

Repeat this process for every return line, cleaner line, and the main drain. For the main drain, blow air through the line until you see a massive eruption of air bubbles in the deep end of the pool. Quickly close the main drain valve at the equipment pad to lock the air inside the pipe, creating a natural air pocket that prevents water from rising into the plumbing.

Line Blower – Cyclone Pro Pipe Blower

A standard shop vac simply does not have the volume or pressure required to push water out of deep underground pool lines. A dedicated line blower uses a high-output motor to force air through long plumbing runs, clearing water from deep main drains and long return loops. Without this specialized tool, water will remain trapped in the low points of your pipes, waiting to freeze and rupture the PVC.

The Cyclone Pro Pipe Blower features a powerful bypass motor specifically engineered to generate up to 130 CFM of air volume at 3 psi. The bypass design protects the motor from overheating when facing backpressure from deep water, ensuring a long operational life. Its rugged, impact-resistant plastic casing protects the unit from drops on concrete pool decks and rough handling.

To get the most out of this blower, utilize the included heavy-duty hose and adapter fittings to establish a completely airtight connection to your pump basket or skimmer. Attempting to hold the hose manually against the pipe openings will result in lost air pressure and an incomplete blowout. * Best for: Dedicated DIY pool owners and neighborhood pool maintenance enthusiasts who want professional-grade blowout capability. * Not ideal for: Pool owners who hire professional closing services, or those living in warm regions where pipes do not need to be cleared.

Cover Pump – Little Giant APCP-1700 Pump

Solid pool covers and safety covers with fine mesh can accumulate hundreds of gallons of water from rain and melting snow over the winter. This standing water creates a massive weight load that strains the cover anchors, pulls on the pool walls, and poses a drowning hazard for wildlife. An automatic cover pump sits on top of the cover, turning on automatically to pump off excess water before it can cause structural damage.

The Little Giant APCP-1700 Pump is a submersible pump designed specifically for pool covers, delivering up to 1,700 gallons per hour of water removal. It features an integrated mechanical float switch that automatically activates the pump when water reaches two inches deep and shuts it off when the cover is dry. The wide, weighted base provides excellent stability, preventing the pump from tipping over on uneven, wind-blown covers.

Keep the pump’s intake screen free of leaves and organic debris, which can clog the impeller and cause the motor to overheat. It is also important to unplug the pump and store it indoors during periods of extreme, sustained freezing temperatures to prevent the internal pump chamber from cracking. * Best for: Owners of solid winter covers or tight mesh covers that collect significant water during winter rains and snowmelt. * Not ideal for: Standard open-mesh safety covers that naturally drain all water directly into the pool.

Pool Brush – Blue Devil Deluxe Wall Brush

Brushing the pool is the final physical prep step before putting the cover on for the winter. Algae spores, calcium scale, and fine dust cling to the pool walls and floor, creating a film that will harden and stain over the winter months if left undisturbed. A vigorous brushing loosens these contaminants, allowing the pool filtration system to capture them or the winterizing chemicals to destroy them.

The Blue Devil Deluxe Wall Brush features a heavy-duty metal back and handle connection, which prevents the brush from snapping when applying heavy downward pressure. Its dense poly bristles are designed to scrub aggressively without scratching delicate vinyl liners or marring plaster finishes. The slightly curved ends allow you to clean tight corners and step transitions with minimal effort.

Always attach the brush to a sturdy telescoping pole and work from the shallow end to the deep end in systematic, overlapping strokes. Pay extra attention to areas behind ladders, around light niches, and beneath the skimmer throat where algae loves to hide. * Best for: All pool owners who want to thoroughly clean their pool surfaces before sealing the water away for the season. * Not ideal for: Cleaning loose, heavy leaves from the bottom of the pool, which requires a leaf vacuum or scoop instead of a brush.

Protecting Your Equipment Filtration System

Once the pool lines are cleared and sealed, you must turn your attention to the filtration system on the equipment pad. Water left inside the pump, filter, heater, or chlorinator will freeze and split the expensive castings. Start by turning off all electrical breakers to the pool equipment to prevent the pumps from accidentally dry-running during the winter.

Remove the drain plugs from the bottom of your pump strainer basket, the filter tank, and any heating units. Store these small plugs inside the pump strainer basket with the lid loosely attached so they do not get lost over the winter. If you have a multiport valve on your sand or DE filter, set the handle to the “Winterize” or “Closed” position to relieve pressure on the internal gasket.

For salt chlorinator systems, remove the electrolytic cell, clean it with a mild acid solution to remove scale, and store it indoors. Leaving a sensitive salt cell exposed to freezing weather can damage the internal plates and lead to premature failure in the spring.

Storing Your Pool Accessories Until Spring

All removable pool accessories must be taken out of the pool, thoroughly cleaned, and stored in a dry, protected environment. Items like ladders, handrails, drop-in steps, and solar covers will deteriorate rapidly if left exposed to harsh winter elements. Wash these items with clean water to remove chemical residues, and let them dry completely to prevent mold growth.

Store your accessories in a shed, garage, or basement away from freezing temperatures and nesting pests. Mice and other rodents love to chew on vinyl solar blankets and pool noodles to build nests, so consider using heavy-duty plastic storage bins to protect these softer items.

Finally, ensure any leftover pool chemicals are stored in a dry, cool area out of direct sunlight and away from moisture. Keep oxidizers separate from acids and liquid chlorines to prevent dangerous chemical reactions in your storage space.

Closing your backyard pool properly with the right gear is the ultimate way to protect your investment and guarantee a hassle-free spring opening. By investing in quality winterizing tools, clearing your plumbing lines, and securing a reliable safety cover, you can rest easy knowing your pool will survive the harshest winter weather unscathed.