Quick answer
Close your pool once the water stays below about 65°F. In the Hudson Valley that’s usually between Labor Day and mid-October. The steps are: balance the water, clean the pool, shock it, lower the water level, blow out and plug the lines, drain and store the equipment, add winter chemicals, and install your cover. Never fully drain a vinyl-liner pool.
A good closing is what makes spring opening easy. Rush it, and you can open your cover in April to green water, a stained liner, or a cracked pipe from a winter freeze. This checklist is the same process we use for in-ground and above-ground pools across Dutchess County, with the steps that matter most in our freeze-and-thaw winters.
When to close your pool in the Hudson Valley
Timing matters more than most people think. Algae grows easily in warm water, so if you close too early while the water is still in the 70s, algae can take hold under the cover. Wait until the water temperature stays below about 65°F. For most local pools, that happens sometime between Labor Day and mid-October. Don’t wait so long that you’re working through a hard freeze with water still in the lines.
What you’ll need
- Pool test kit (or a water sample to bring to our store for free testing)
- Balancing chemicals, chlorine shock and a winter algaecide
- Skimmer net, brush and vacuum
- Shop vac or air blower for blowing out the lines
- Winterizing plugs for the returns and a skimmer plug or ice compensator (such as a Gizzmo)
- A submersible pump, or a way to lower the water level
- Your winter or safety cover (plus an air pillow for above-ground pools)
Step-by-step: how to close a pool for winter
- Balance the water a few days ahead. Aim for a pH of about 7.2–7.8 and total alkalinity of about 80–120 ppm. Balanced water protects your liner and surfaces through months of sitting still.
- Clean the pool thoroughly. Skim, brush the walls and floor, and vacuum. Empty the skimmer and pump baskets. Leaves left on the floor all winter can stain a vinyl liner.
- Shock, then add winter algaecide. Shock the pool a few days before closing and keep the filter running. Once chlorine has come back down, add a winter algaecide according to the label. Very high chlorine trapped under a cover can fade a vinyl liner.
- Clean the filter. Backwash a sand or DE filter, or hose off a cartridge filter, so it goes into storage clean.
- Lower the water level. Pump the water down below the skimmer opening and return jets. If you have a Loop-Loc safety cover, Loop-Loc specifies 15–18 inches below the top of the pool for mesh covers and 12–16 inches for solid covers. That level helps the cover support snow. Do not drain a vinyl-liner pool. The liner can shrink, and groundwater can push the floor up.
- Blow out and plug the lines. Use a shop vac or blower to push all the water out of the skimmer and return lines, then plug the returns with winterizing plugs and seal the skimmer. Some owners also add pool-rated antifreeze to the lines. Never use automotive antifreeze.
- Drain and store the equipment. Turn off power at the breaker. Remove the drain plugs from the pump, filter and heater so no water is left to freeze and crack them, and store small parts indoors. If you have a salt system, winterize the cell and controller according to the manufacturer’s instructions.
- Remove ladders, rails and accessories. Take out ladders, handrails, removable steps and robotic cleaners. Clean them and store them out of the weather.
- Install your cover. A safety cover should sit tight, like a trampoline, with no gaps or sagging. Solid covers without a drain panel need a cover pump to keep standing water off.
Closing an above-ground pool: what’s different
- Water level: lower it to just below the skimmer. Don’t drain it any further.
- Hoses and fittings: disconnect the hoses from the skimmer and return, drain them, and plug the wall fittings.
- Air pillow: inflate an air pillow and center it under the cover. It gives ice room to expand and helps rain and snow run off instead of pooling in the middle.
- Cover: secure the winter cover with its cable and winch so wind can’t get under it.
- Equipment: drain the pump and filter and store them in a garage or shed if you can.
Caring for your covered pool over the winter
With a safety cover, the work is mostly done. According to Loop-Loc, there’s no need to shovel snow off a safety cover. Do check the water level from time to time as snow melts. Letting the water drop too far puts extra stress on the cover and can void its warranty. If you use a pump on a solid cover, keep an eye on it so it doesn’t drain the pool itself.
When to call a pro: Freeze damage to underground plumbing is one of the most expensive repairs a pool owner can face. If you have a heater, complicated plumbing, or you’ve never blown out lines before, a professional closing is worth it. Classic Pools is now scheduling pool closings. Call (845) 297-0004.
Thinking about a new cover? We carry Loop-Loc mesh and solid safety covers. And if your liner showed its age this summer, the off-season is a good time to plan a liner replacement for spring.
Frequently Asked Questions
When should I close my pool in New York?
Once the water temperature stays below about 65°F. In the Hudson Valley that’s usually between Labor Day and mid-October. Closing while the water is still warm makes it easier for algae to grow under the cover.
Should I drain my pool for the winter?
No. Never fully drain a vinyl-liner pool. The liner can shrink, and groundwater can push up on the floor. Lower the water below the skimmer and returns, or to the level your safety cover manufacturer recommends.
How low should the water be for a safety cover?
Loop-Loc specifies 15–18 inches below the top of the pool for mesh safety covers and 12–16 inches for solid safety covers. That level helps the cover support the weight of snow.
Do I need to remove snow from my pool safety cover?
Loop-Loc says there’s no need to clear snow from a safety cover. Just check the water level periodically, especially as snow melts, so it doesn’t drop too low.
Can I close my pool if the water is green?
Clear it first. Closing with algae in the water almost guarantees a green pool in spring and can stain the liner. Shock, brush and filter until the water is clear and balanced, then close.
Questions about your pool?
Stop by our Poughkeepsie store at 1820 New Hackensack Road or call (845) 297-0004. We're happy to help.
