It’s true—summer is almost over already (at least for those of us in the Northeast). Gone are the days when we complained about the heat and cooled off with a quick swim. As the nights get colder, so does your pool water. Since the typical pool season runs from Memorial Day to Labor Day, it’s time to think about closing things down.
Proper winterization is key to protecting your pool liner, equipment, and plumbing. Below is a step-by-step process to help you prepare your pool for the off-season. Be sure to read through everything before starting—there’s some prep and planning involved!
Equipment & Materials Checklist
✅ Cleaning equipment (skimmer, vacuum, brush)
✅ Chemical test kit
✅ Siphon or small submersible pump (unless you have a sand filter)
✅ Winter plugs for inlet fittings
✅ Winterizing chemicals (shock, algaecide, scale/stain remover)
✅ Pool cover
✅ Air pillows (for aboveground pools)
Step 1: Clean Your Pool
Before doing anything else, make sure your pool is sparkling clean. The cleaner it is at closing, the cleaner it will be when you open it in spring. Scrub the sides and bottom with a brush and vacuum thoroughly. This is one job where you shouldn’t rely on your robotic or automatic cleaner—manual vacuuming is best.
Step 2: Test & Balance
Balance your water chemistry before adding winterizing chemicals. Ideal ranges are:
💧 pH: 7.4 – 7.6 ppm
💧 Total Alkalinity: 100 – 150 ppm
💧 Calcium Hardness: 200 – 400 ppm
💧 Chlorine: 1 – 3 ppm
If adjustments are needed, always add chemicals in this order:
1. Alkalinity
2. pH
3. Calcium hardness
4. Chlorine
Step 3: Add Winterizing Chemicals
Once your water is balanced, it’s time to add your closing chemicals. Most winter kits include a shock and an algaecide. As a general rule, use 1 lb. of shock and 1 qt. of algaecide per 10,000 gallons of pool water. For extra protection, you can also add a stain and scale remover (follow the product instructions carefully).
👉 Looking for a simpler approach? Consider using a WinterPill — an all-in-one winterizing chemical option that slowly releases throughout the off-season. It helps control algae, clarifies water, and reduces scale and stain build-up, making spring opening even easier.
Whichever method you choose, be sure to add your chemicals about 24 hours before officially closing the pool.
Step 4: Closing It Down
This step protects your pool and equipment from freezing temperatures. Start by removing ladders, steps, toys, and accessories. Then choose one of two common winterizing methods:
Option 1: The No-Drain Method
This method keeps your water level full and uses specialized plugs and covers. You’ll need an Aquador skimmer cover, a Gizzmo skimmer plug, and return plugs.
1. Install the skimmer cover and screw in the Gizzmo plug.
2. Remove directional fittings and install winter plugs in the returns.
3. Disconnect all hoses/piping from the pump and filter.
4. Prep your filter:
-Sand Filter: Move multiport to Winterize, remove drain plug, sight glass, and bleeder valve.
-D.E. Filter: Remove drain, rinse grids, leave valves open.
-Cartridge Filter: Remove drain plug and cartridge, clean and store indoors.
5. Remove the drain plug from the pump.
6. Store all small parts in the pump strainer basket for easy access in spring.
Option 2: The Drain-Down Method
This is the more traditional approach. You’ll lower your water level about 4–6 inches below the skimmer.
1. Drain water using your filter’s “waste” setting or a submersible pump.
2. Blow out suction and return lines with a shop vac or blower, then plug them with winter plugs.
3. Add non-toxic pool antifreeze to plumbing lines for extra protection.
4. Prepare pump and filter as described in Option 1.
Step 5: Covering the Pool
Aboveground pools: Inflate air pillows and secure them in the center of the pool before installing your winter cover. The pillows help reduce ice pressure and protect the walls.
Inground pools: Install a high-quality safety cover or solid winter cover, ensuring it is tightly secured to keep out debris.
Final Tips
✅ Double-check that all equipment is drained and stored indoors where possible.
✅ Keep extra plugs and gaskets handy for spring reopening.
✅ Use a quality winter cover (and water bags if needed) to protect your pool all season.
Ready to Get Started?
At Poolweb.com, we stock everything you need for winterization: from winter chemical kits and skimmer winter plugs/covers to air pillows and pool covers.
With the right prep, you’ll protect your investment and make spring pool opening a breeze!
Still feeling unsure? If you prefer a visual guide, check out Swim University’s YouTube videos on winterizing. They provide clear, step-by-step demonstrations that make the process easy to follow. You can watch them now or bookmark them for later!
Above Ground Pool Winterizing:
Video courtesy of Swim University.
Inground Pool Winterizing:
Video courtesy of Swim University.