How to Winterize an Above Ground Pool Step by Step
Winterize your above ground pool the right way. A clear step-by-step guide covering cleaning, chemicals, draining, and covering to avoid spring damage.
By TheYardForge — outdoor and garden gear, analyzed honestly for real backyards
You finally got the pool balanced mid-July, and now the leaves are turning and the water is getting too cold to enjoy. Closing an above ground pool feels like a chore, but skipping it or rushing through it is a fast track to a green, stained, or cracked mess in spring. The direct answer is this: winterizing is a sequence, not a single task. You need to deep-clean the water, balance the chemistry, protect the plumbing and pump, lower the water level, drain the equipment, and cover everything securely. Do those in order, using the manufacturer's guidelines for your specific pool and chemicals, and you will open to clear water instead of a swamp. Here is exactly how to do it without overcomplicating things.
Step-by-Step Winterizing Process
Closing the pool properly takes an afternoon. Based on what pool owners report year after year, here is the most reliable order of operations. Before you start, grab a good test kit, your winter cover, and any winterizing plugs included with your pump and filter.
Deep-clean the pool while it is still running. Brush the walls and floor, vacuum thoroughly, and skim every leaf. The cleaner the water going into winter, the easier spring opening will be.
Balance and winterize the water chemistry. Test the water and adjust pH, alkalinity, and sanitizer levels according to your product labels. For exact winter chemical dosages, follow the instructions on your winterizing kit or ask a pool professional. Never guess with chemicals.
Run the pump for 24 hours. After adding any winter chemicals, keep the system running a full day so everything circulates evenly and nothing settles in one spot.
Lower the water level. Drain the water to just below the skimmer and return fittings. For most above ground pools, that is roughly 4 to 6 inches below the skimmer mouth. This protects the skimmer from freezing damage. Check your pool's manual for the recommended level.
Drain the pump, filter, heater, and hoses. This is critical. Remove drain plugs, open the air relief valve, and let all water escape. Tilt or blow out lines if your setup requires it. Any water left inside will freeze and crack something expensive.
Remove and store equipment indoors. Bring the pump, filter, chlorinator, and hoses into a garage or shed. If something must stay outside, wrap it tightly to keep moisture and pests out.
Install a winter cover. Use a proper above ground pool winter cover, not a thin solar cover. Secure it with a cable and winch so wind cannot lift it. Add an air pillow under the cover if you live somewhere with heavy ice, as it absorbs pressure from expanding ice and reduces stress on the walls.
Clear debris off the cover periodically. Leaves and water pooling on top of the cover in late autumn can stretch it and pull it into the pool. Check it after storms.
Common Winterizing Methods Compared
There is more than one valid way to close a pool. Here is how the main approaches stack up based on what owners and pros actually recommend.
| Method | What you do | Best for | Main drawback |
|---|---|---|---|
| Full drain | Empty most of the water and leave the pool dry all winter | Very cold climates with deep freezes | Risk of liner shrinking or wall damage from wind |
| Partial drain with cover | Lower water below the skimmer, keep most water in place, add winter chemicals, cover | Most climates and typical above ground pools | Requires a quality cover and occasional maintenance |
| Air pillow plus cover | Partial drain, float an air pillow in the center, secure cover over it | Regions with heavy ice and snow | Pillow can shift or deflate; cover needs monitoring |
For the vast majority of above ground pool owners, partial drain with a good cover is the safest and easiest route. A full drain is rarely the right call unless your manufacturer explicitly recommends it for your specific model and climate.
Where This Fits in a Real Backyard
If your pool sits on ground you leveled yourself, double-check that everything is still solid before covering. A small shift over summer can let water pool unevenly under the cover and strain one wall. Our guide on leveling ground for a pool without the headache walks through that if you need a refresher. And if you are closing a pool for the first time and wondering whether your setup was ideal from day one, the above ground pool buying guide for real backyards is worth a look before next season.
The honest truth most guides skip is that winterizing is only half the job. The other half is picking a covering method that matches your actual winter, not the winter you wish you had. Mild-weather owners who over-drain or over-cover sometimes create more problems than they prevent, while cold-climate owners who skip the air pillow pay for it with a stretched cover or a cracked skimmer.
FAQ
How far below the skimmer should I drain my above ground pool?
For most above ground pools, drain the water to about 4 to 6 inches below the skimmer opening. Always check your pool manufacturer's manual, since some models have different recommendations.
Can I leave my above ground pool full all winter?
It is not a good idea in freezing climates. Water expands when it freezes, and a completely full pool with water in the skimmer and plumbing is a recipe for cracked fittings and damaged walls. Lowering the water below the skimmer is standard practice.
What happens if I forget to drain the pump before winter?
Any water left inside the pump, filter, or hoses can freeze and crack the housing or fittings. Even a small amount of trapped water can cause expensive damage. This is the step most often skipped and most often regretted in spring.
Do I need to add winter chemicals if I cover the pool?
Yes, in most cases. Winterizing chemicals help prevent algae growth and keep the water from turning into a swamp under the cover. Follow the exact dosing on your winterizing kit or consult a pool professional, since overdosing or mixing the wrong products is dangerous.
Is an air pillow really necessary under a winter cover?
It helps in areas with heavy ice and snow because it absorbs pressure from expanding ice that would otherwise push against the pool walls and cover. In mild climates with no hard freezes, it is less essential. Consider your local winter before deciding.
Can I use a solar cover instead of a winter cover?
No. A solar cover is designed to warm water, not protect a closed pool through months of weather, leaves, and ice. Use a proper winter cover sized for your pool and secure it tightly with a cable and winch.
Winterizing well is mostly about order and patience. Clean, balance, drain equipment, lower water, cover securely. Do it at the right time, before the first hard freeze, and you will open in spring with a much easier cleanup. Skip a step, especially draining the pump, and you will know exactly which part you skipped when the weather warms up.