Seasonal Pool Care /
How to Winterize an Inground Pool Safely
Winterizing an inground pool means cleaning, checking water balance, lowering the water level as directed, protecting plumbing and equipment, and installing a winter cover.
Archive date: this article was written for PoolSkimmer on Oct 23, 2026 and given the earlier archive date of Sep 12, 2026 so the blog reads as an organized archive. It was not published on that date.
Winterizing an inground pool: a guide
The process of winterizing an inground pool is straightforward once you have the right approach. It involves a thorough cleaning, making sure the water is in balance and at the proper level for your pool’s design, and putting in place a cover to shield the skimmer and plumbing from hard freezes. Be sure to consult the manuals that came with your pump, filter, heater and valves. And as a rule, the pump should be off before one opens any basket.
Where to begin
You want to start with a system that is clean and in good order. Leftover debris will only make spring opening more of a chore, or worse, clog the skimmer and leave stains on the surfaces. A methodical closing sequence is best:
1. Skim off any leaves or floating matter. 2. Give the walls, corners, ladders and steps a good brushing. 3. Vacuum the floor to remove what has settled. 4. Shut down the pump prior to taking out the skimmer or pump basket. 5. Service the filter per the manufacturer’s directions.
Should the pool equipment be acting up, or if the filter is long past due for service, it is wiser to have a qualified professional take a look before you put the pool away for the season.
Water levels
Most owners will lower the water ahead of winter to keep freezing water from the skimmer opening or other sensitive spots. There is no one size fits all; the correct level is dictated by your cover type and skimmer style, so refer to the pool manual.
A few things to bear in mind:
- Never put a hand in suction equipment while it is running.
- If there are special instructions for plugs or drains, do not guess.
- Adhere to the equipment manual if your system has a main drain or plumbing plugs.
- Leave electrical work alone. Damaged cords or a burning smell are not something to tinker with.
While a pool in a milder climate may not need as much attention as one in a region with real cold, the exposed plumbing still needs protection.
Dealing with chemicals
Water chemistry should be addressed before the cover goes on. Test the water and make adjustments following the label to get a balanced result rather than going through the motions with chemicals. We do not provide mixing recipes or specific dosages here; stick to what the source guidance and manufacturer say.
Do not mix pool chemicals. Follow each product label and the equipment manufacturer's directions; never apply a winterizing product in a manner that runs counter to its instructions. If the water is green or has an odd smell, the problem should be resolved first.
Equipment and the cover
Protect the equipment and plumbing from freezing using the closing instructions for your specific system. Follow the pump, filter, heater and pool manuals, and use a qualified pool professional if the required procedure is unclear.
When you are ready to put on the cover, make sure it is the right fit for the pool and tension it according to the instructions. An air pillow or similar accessory should only be used if the product and pool call for it. A clean, well secured cover will not let debris stretch it out.
When to bring in a pro
If the pool has a heater or an automation system, or if you are faced with a cartridge or sand filter you have not worked on before, a technician can be of assistance. The same goes for any leaks, cracked fittings or electrical issues you might uncover. A proper job done now will save you from trouble in the spring.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)
- [Pentair U-3 skimmer manual: suction safety warnings](https://www.pentair.com/content/dam/extranet/nam/pentair-pool/pool-manuals/u-3-skimmers/395010028C.pdf)
- [SwimmingPool.com: Cleaning the skimmer basket](https://www.swimmingpool.com/maintenance/pump&filter/cleaning-the-skimmer&pump-basket)
- [CDC: Use pool chemicals safely](https://www.cdc.gov/healthy-swimming/media/pdfs/Pool-Chemical-Safety-USE-poster-p.pdf)
- [CPSC: Electrical safety in and around pools](https://www.cpsc.gov/safety-education/safety-guides/pools-and-spas/dont-swim-shocks-electrical-safety-and-around-pools)