How to Winterize a Pool of Any Kind
Updated: Jan. 12, 2023It's important to winterize your pool for the colder months, especially if temperatures in your area drop near or below freezing. We'll take you through the important steps.
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Make Sure You Have a Pool Cover
Properly protecting an in-ground pool requires a pool cover for safety and protection, so choose a durable version. An in-ground pool cover may need to be custom-made depending on your pool shape and size. Mesh covers are lighter and more affordable but offer less protection than full covers. It’s best to choose a cover that’s made for winter use.
Balance pH Levels
When it’s time to winterize your pool, check your pH levels one last time and add more chemicals if necessary to help keep your pool safe. It’s good to have your in-ground pool balanced when working on winterization steps.
Scrub the Pool Walls
Even trace amounts of algae can spread over the winter and cause problems. A pool brush can help you scrub the walls and floor of the in-ground pool. But it’s also important to be thorough, even if the walls look clear. This is also the time to repair to any cracks or damage.
Clean Out the Pool
Use a leaf net or hand skimmer to remove any obvious debris when you winterize your pool. And run the pool so the filter gets a chance to clean out smaller particles.
It’s important to make the remaining water as clean as possible, because any debris can cause problems if it’s trapped over winter. And chemical cleaners can only do so much. If you have an automated in-ground pool cleaner, run it, then remove and store it for next season.
Partially Drain Out the Pool Water
Check your pool cover instructions to see if they specify how to drain a pool for winterization. Mesh covers tend to require an in-ground pool level around one foot below the waterline tile. Thicker covers designed to float usually need the water level lowered three to five inches.
Remove and Clean the Pool Filter
Diatomaceous earth filters need special attention when winterizing a pool. Remove the pool filter and clean up any “dust” leftover in the pump — you don’t want it staying around over winter.
Cartridge filters are a bit easier, but you still need to remove the cartridge and its connector hoses for storage. This is also the time to drain booster pumps, chlorinators and other components your in-ground pool may use.
Add Winterization Chemicals
There are “closing” or winterization chemical kits that you can easily find online. These kits use preparation chemicals and slow-release floaters to keep the water protected and the pool walls clean over winter.
Make sure you use a kit rated for your in-ground pool filtration type. And read instructions carefully to avoid making any mistakes.
Blow Out Your Pool Lines If Necessary
When winterizing a pool, blowing out pool lines is a good idea, since standing water in the lines can stagnate or even freeze if temperatures drop low enough.
You can blow out your pool lines with an air compressor or a wet-rated, powerful shop vacuum if you have the right components. But it’s important to be thorough. Blow out pump components, heaters and filter components (this is a good time to clean skimmer filters). Start with the suction side and move to the pressure side.
Remove Drain Plugs
Remove all drain plugs in your pool. And don’t just go for the drain plugs that you see. Check your manuals and make sure that all drain plugs in all components are removed. This may take a little patience the first time. But it’s easy to learn what the plugs look like and where to search for them.
Insert Expansion Plugs
Expansion or winterizing plugs are designed to help prevent damage caused by freezing water. If temperatures get low in your area, you should you these plugs. They protect skimmer lines (which may require skimmer guards), return lines and cleaner lines. For particularly cold weather, you may also want to add in-ground pool antifreeze to the lines.
Shock Your Pool if Necessary
Read your winterization kit instructions to see if it suggests shocking your pool with a burst of chemicals right before cover-up. The kits may also include shock packs as part of the process. If advised, this should be one of your last steps.
Clear Your Timer, Shut Down Power and Cover the Pool
Shut down power to the in-ground pool by switching off your pool breaker or any equivalent shut-down process. It’s also a good idea to clear your pool timer fully so that if power is restored, your pool won’t accidentally turn on. The pool will be damaged if it runs when winterized. Apply the pool cover, and we’ll see you next spring!
Winterizing a Saltwater Pool
The steps for winterizing an in-ground saltwater pool are similar to those for a chlorine pool, with one important distinction. After you’ve lowered the water level, remove the salt cell.
First, turn off all the equipment, then disconnect the salt generator cell at both ends. Replace it with a dummy bypass cell for the winter. Clean out the salt cell and store it in a dry environment. Then follow the other steps for pool winterization.
Winterizing a Permanent Above-Ground Pool
The steps to winterizing a permanent above-ground pool are largely the same as for an in-ground pool, except that you have to detach and store all the above-ground pool water lines. Let the water run out of them and make sure they’re completely dry before storing them in a dry, protected space. Disconnect the lines at the same time you disconnect power and cover the pool.
If you live where prolonged freezing temperatures are possible, invest in an air pillow under the pool cover. Inserted in the middle of pool, this oversized, inflatable pillow takes the pressure off the cover should the pool water freeze. And it helps reduce snow and ice accumulation over the cover.
Winterizing a Portable Above-Ground Pool
Experts agree that the best way to winterize a portable above-ground pool is to drain it, disassemble it and pack it away until next year.
Before you drain your pool, balance the chemicals to ensure that the pool water won’t damage the environment. Let the pool air dry, and use towels and a shop vac to dry out any remaining wet areas. Fold up the pool and store it in a dry area where it won’t be exposed to mice or other nesting animals.