Seasonal Pool Care /
How to Winterize an Above Ground Pool: 10 Steps for Closing the Pool
Winterizing an above ground pool means cleaning, lowering the water as the manual directs, protecting the pump and filter, and fitting a secure winter cover before freezes begin.
Archive date: this article was written for PoolSkimmer on Oct 23, 2026 and given the earlier archive date of Oct 2, 2026 so the blog reads as an organized archive. It was not published on that date.
Proper winterization of an above ground pool is a matter of thorough preparation: clean the pool, get the water in order, and put on a secure cover well before any hard freezes set in. You will need to lower the water level as your manual specifies and take steps to shield the pump and filter from the cold. When it comes to drain points, plug locations or how much chemical to use, there is no room for guesswork. Stick to what is written on the equipment manual and the labels, and do not hesitate to engage a pool professional if you are dealing with an unusual or damaged setup.
Timing your pool closing
You should begin the process of closing the pool once consistent winter weather and freezing nights make routine maintenance too risky. As a rule of thumb, if you can still safely brush and vacuum the pool, that is the time to do it. A pool that has been regularly skimmed and brushed while in use is far easier to winterize; debris left behind can clog the skimmer or stain surfaces.
The first steps in winterizing
A safe cleanup sequence is the way to start:
1. Before you open a skimmer or strainer basket, shut off the pump. 2. Get rid of floating leaves and insects. 3. Brush down the walls, floor and accessories to work the dirt loose. 4. Vacuum what has settled at the bottom. 5. Clean the filter in accordance with the manufacturer’s directions.
Once the pool is tidy, give the equipment and the area around it a once over. Check for anything amiss with the hoses, valves or fittings, and put away any loose accessories that have no business being left out. Make sure your winter cover and its hardware are in good shape.
Dealing with water chemistry
Your aim is to leave the water clean and balanced so algae and scale are not a problem come spring. Follow the pool manual and the chemical labels to the letter.
Some things to keep in mind:
- Test the water prior to closing.
- Never mix chemicals unless the label deems it safe.
- Should the water be cloudy, green or stubbornly unbalanced, have a pro look at it before you close up shop.
How much to drain
Every above ground pool is different, so there is no one size fits all when it comes to draining. The right level is dictated by the design of the pool and the skimmer. You want to lower the water enough to spare the plumbing from freeze damage, but not so much that the liner or wall is without support. If you cannot find the manual, let a qualified professional determine the target level for you.
Protecting the equipment
The objective here is to keep water from freezing inside the system. Since setups vary, you must follow your equipment manuals. This might mean disconnecting hoses or removing drain plugs only when instructed. Do not put your hands into operating suction equipment. And if you are not certain of the valve layout or whether you have a sand filter or a bottom drain, it is better to call for assistance than to force parts apart.
Putting on the cover
For the final step, put on a winter cover that sits securely and is clear of any sharp edges. Some will opt for an air pillow underneath, but that is more of a preference than a necessity. Once it is on, make sure it holds firm through the season, particularly after a storm or heavy snowfall.
Reasons to call in a pro
There are times when you should leave it to the experts. Call a pool professional if you are faced with electrical problems, damaged plumbing or a pump, or if you are unsure how to safely plug or drain the lines. An unfamiliar system without a manual is also grounds for a phone call. A methodical job now will prevent freeze damage and make opening the pool in the spring a lot less of a chore.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)