How To Close An Above Ground Pool: A Complete Professional Winterization Guide
Closing an above ground pool requires a systematic reduction of water levels, chemical stabilization to prevent algae blooms, and the installation of a high-quality, tension-secured winter cover. By following specific technical protocols—such as purging all plumbing lines and utilizing expansion plugs—you effectively protect the pool structure and filtration system from the destructive forces of freeze-thaw cycles.
Pre-Operation Requirements and Essential Winterization Inventory
Effective pool closure is less about cleaning and more about environmental sealing. Before beginning the procedure, ensure you have the necessary supplies to prevent hydrostatic damage and equipment failure. Improper winterization can lead to cracked skimmers, burst hoses, and structural corrosion.
- Essential Chemical Kit: Winterizing algaecide, slow-release chlorine tablets or non-chlorine shock, and a pH balancing agent.
- Equipment & Tools: Expansion (ice) plugs, threaded pool plugs, teflon tape, a submersible cover pump, and a high-quality winter pool cover.
- Structural Supports: A cover winch and cable, pool cover clips (or wall bags), and a skimmer guard or ice compensator.
- Duration & Budget: Allocate 4 to 6 hours for a standard 18-foot to 24-foot round pool. Anticipate a budget of 150 to 300 dollars for specialized winter chemicals and hardware replacements.
Step-by-Step Technical Execution for Winterization
Step 1: Deep Cleaning and Chemical Balancing
Begin by removing all organic debris from the pool floor using a manual vacuum. Leaves and decaying matter create an acidic environment that can stain liners over the winter. Once the pool is clear of debris, test the water using a high-precision digital or drop-test kit. Adjust the total alkalinity to between 80 and 120 parts per million (ppm), and ensure the pH level sits comfortably between 7.4 and 7.6. Finally, shock the water with a non-chlorine oxidizer to eliminate pathogens. Wait at least 24 hours for the chemicals to circulate before proceeding to the next step.
Pro-Tip: Do not use heavy-duty copper-based algaecides if you have a metal-walled pool, as this can accelerate corrosion during the winter months. Use a polymer-based algaecide instead.
Step 2: Water Level Management and Plumbing Purge
For an above ground pool, you must lower the water level to approximately 4 to 6 inches below the skimmer intake. If you allow the water to remain at the skimmer level, water trapped in the housing will freeze and crack the plastic, leading to catastrophic leaks come spring. Once the level is lowered, disconnect the return lines and the hose leading to the pump and filter. Drain the filter tank, the pump housing, and the chlorinator. Use a shop vacuum to blow air through the return lines to ensure they are entirely devoid of moisture.
Warning: Never leave water inside the pump or filter tank. Even a small amount of residual water can expand upon freezing and shatter the internal housing, which is an expensive component to replace.
Step 3: Installing Expansion Plugs and Skimmer Protection
Insert expansion plugs into the return jets to seal the pool wall against water intrusion. Apply teflon tape to the threads of your winterizing plugs to ensure a watertight seal. For the skimmer, install an ice compensator or a specialized skimmer guard. This device acts as a buffer; as water in the skimmer housing freezes, the plastic compensator absorbs the outward pressure, preventing the rigid skimmer walls from cracking. If you do not have a skimmer guard, use a clean plastic milk jug filled with a few inches of pebbles to provide the same compression buffer.
Step 4: Final Cover Deployment and Tensioning
Secure the winter cover across the pool surface. For above ground models, wrap the steel cable through the grommets of the cover and tighten it using the provided winch. The cover should be taut enough that it does not flap in the wind, as excessive friction against the top rails will lead to premature wear and tearing. Utilize cover clips or heavy-duty wall bags to secure the edges to the vertical uprights. If you anticipate heavy snow loads, consider using a cover pillow—a large, air-filled bladder placed in the center of the pool under the cover—to distribute weight and prevent water from pooling on top.
The Best Above Ground Pool Deck Materials: Durable & Stylish Options
Technical Specifications for Winterization Components
| Component | Function | Maintenance Threshold |
|---|---|---|
| Expansion Plug | Seals return lines against freeze | Replace every 2-3 seasons |
| Skimmer Guard | Prevents skimmer housing cracks | Inspect annually for hairline fractures |
| Winter Cover | Prevents debris and light entry | Replace if material becomes porous |
| Winter Algaecide | Inhibits organic growth in dormancy | Use specialized 6-month formula |
Common Site Failures and Field Fixes
- Root Cause: Excessive Water Pooling on Cover. If rainwater accumulates on the cover, the weight can cause the pool walls to buckle or the cover to rip.
- Actionable Fix: Use a submersible cover pump to actively remove standing water throughout the winter. If the cover continues to sink, check the tension of your winch or adjust the placement of the air pillow.
- Root Cause: Green Water Upon Opening. This typically indicates that the chemical levels were improperly balanced, or the algaecide was diluted too early.
- Actionable Fix: Ensure that you use a "slow-release" winter kit. If you live in a region with long, mild autumns, consider adding a supplemental dose of winter algaecide in late November.
- Root Cause: Damaged Return Jets. Failing to purge the return lines allows water to remain in the piping, where it freezes and expands.
- Actionable Fix: Always blow out lines with a shop vacuum from the pool side toward the equipment side. If you suspect a leak, use a specialized pool putty to seal minor stress cracks before they expand.
Frequently Asked Questions
Can I leave my pool filter outside during the winter?
While you can leave the filter housing outside, you must remove the drain plug and the pressure gauge. It is highly recommended to store the pump motor and the filter internal grids inside a garage or shed to protect them from moisture and extreme temperatures.
How low should I drain my above ground pool for winter?
You should drain the water to approximately 4 to 6 inches below the skimmer intake. Never drain the pool completely, as the pressure from the surrounding soil and the lack of internal water pressure can cause the liner to pull away from the walls or the structure to collapse.
Do I need to remove my pool liner before winter?
No, the liner should remain in the pool throughout the winter. Removing the liner exposes the pool wall to direct contact with freezing conditions and debris, which significantly decreases the lifespan of the steel or resin structure.
How do I keep the cover from blowing off during storms?
Ensure your winch is tightened to maximum capacity and use cover clips every 2 to 3 feet around the perimeter. If you live in an exceptionally high-wind area, consider wrapping the entire pool circumference with a heavy-duty ratchet strap to hold the cover edges firmly against the uprights.
Invest in high-quality winterization supplies today to ensure your pool remains structurally sound throughout the off-season. Consult our comprehensive seasonal maintenance catalog to find the exact expansion plugs and chemical kits required for your specific pool dimensions.
