How to Winterize a 24-Foot Above-Ground Pool

Your 24-foot above-ground pool had a great summer. It hosted cannonballs, sunscreen slicks, and at least one suspiciously soggy bag of chips. Now the weather’s turning, and your pool is about to face its annual nemesis: freezing water that expands like it’s trying to win a strongman contest. The goal of winterizing is simplekeep water clean, keep plumbing and equipment dry, and keep spring opening from turning into a swamp-themed escape room.

This guide walks you through a reliable, DIY-friendly closing process that works for most 24-foot round above-ground pools (especially vinyl-liner setups), with smart options depending on your skimmer style, cover type, and whether your “plumbing” is flexible hoses or hard pipe.

Quick Reality Check: When Should You Close?

Timing matters more than most people think. Close too early and you’re basically tucking algae into bed with snacks and a warm blanket. Close too late and a surprise freeze can crack equipment or split a hose.

• Best rule of thumb: Start winterizing when water temperature is consistently around 65°F or lower.
• Finish before: the first hard freeze in your area.

What You’ll Need (So You Don’t Have to “Improvise”)

Gather everything first. Mid-project hardware-store trips are how winterizing becomes a trilogy.

• Water test kit or test strips
• Pool brush, leaf net, vacuum (manual or robotic)
• Winterizing chemical kit (or shock + algaecide + optional stain/scale control)
• Submersible pump or siphon setup (for lowering water level if needed)
• Winter plugs for return(s) and skimmer solution (Gizzmo, skimmer plate, or skimmer guarddepending on your setup)
• Winter cover sized for a 24′ round above-ground pool + cable/winch (or your cover’s securing system)
• Air pillow: commonly 4′ x 8′ for many 24′ round pools
• Wrench/screwdriver, Teflon tape, spare O-rings, and a labeled bag for small parts
• Optional but helpful: shop vac or blower, cover pump, leaf net, enzyme/clarifier

Know Your Pool Volume (Because Chemicals Don’t Guess Well)

A 24-foot round pool typically holds roughly 12,000–15,000 gallons depending on water depth. That number matters for dosing shock, algaecide, and closing kits.

If you want to estimate it:
Gallons ≈ 3.1416 × (radius in feet)² × (average water depth in feet) × 7.48

Example: radius 12′, average depth 4′ → 3.1416 × 144 × 4 × 7.48 ≈ 13,500 gallons. If your kit is labeled “up to 15,000 gallons,” you’re in the right neighborhood.

Step-by-Step: How to Winterize a 24-Foot Above-Ground Pool

Step 1: Do a “Last Clean” Like Future-You Is Watching

Anything left in the pool over winter will stain, rot, or throw a party. Skim the surface, brush the walls, vacuum the floor, and empty skimmer baskets. Pay extra attention to dead spots where circulation is weakthose areas love to turn green when you’re not looking.

Step 2: Backwash or Clean the Filter

Give your filtration system one last proper cleaning so you’re not sealing in a season’s worth of gunk.

• Sand/DE: backwash per your manual. Rinse after backwashing if your valve has that setting.
• Cartridge: remove and hose it clean (or use a cartridge cleaner), then let it dry.

Step 3: Shock the Pool (A Few Days Before You Fully Close)

Run the pump and shock the water a few days before the final shutdown. This helps knock out contaminants so the water doesn’t spend winter marinating in them.

Pro move: circulate long enough for the shock to do its job, then test again before adding your closing kit.

Step 4: Balance the Water Chemistry (This Is the “Spring You” Gift)

The cleaner and more balanced the water is at closing, the less dramatic your spring opening will be. Aim for these common closing targets:

• Total Alkalinity: 80–150 ppm
• pH: 7.2–7.6
• Calcium Hardness (vinyl/fiberglass liners): about 175–225 ppm
• Free chlorine: around 4 ppm before you’re done balancing/sanitizing

Adjust alkalinity first, then pH. Keep the pump running while you add chemicals, and follow label directions exactly.

Step 5: Add Winterizing Chemicals (Closing Kit = Convenience)

Most people use a winterizing kit because it bundles the essentials. Typical closing chemistry includes:

• Shock (chlorine or non-chlorine)
• Winter algaecide
• Optional stain/scale or “metal control” (especially helpful with well water or certain heaters)
• Optional enzymes/clarifiers for reduced scum and spring funk

Run circulation after adding chemicals so they distribute evenly. And yes, it’s worth repeating: don’t mix chemicals together. Add each product to the pool water separately as instructed.

Step 6: Decide Your Water Level Strategy (Drain a Little… or Use a Skimmer Solution)

For many above-ground pools, you’ll lower the water level to just below the skimmer opening so water can’t freeze inside and crack it. But some setups allow you to skip draining by using a skimmer winterizing plate or an internal skimmer protection device.

Common options:

• Lower water level: drain to just below the skimmer mouth (often a few inches below).
• Use a skimmer guard/Gizzmo/skimmer plate: protects the skimmer so you may not need to drain as much (or at all, depending on the product and pool).

Specific to many 24-foot rounds: If you’re using a solid winter cover and want less hassle, many owners prefer a skimmer plate or Gizzmo-style approach. If you’re using a mesh cover, you may need to lower the water more to account for precipitation passing through (check your cover instructions).

Step 7: Winterize the Skimmer and Return Fittings (Where Freeze Damage Loves to Happen)

Skimmers and return jets are prime freeze targets because trapped water expands. Your exact steps depend on whether you have flexible hoses or hard plumbing, and what skimmer style you have.

• Returns: remove the directional “eyeball” fitting (if you have one), then install a winterizing plug in the return fitting.
• Skimmer: remove the skimmer basket and use the protection method that matches your system (Gizzmo/skimmer guard/plate).

If your pool uses a Gizzmo-style skimmer protection device and a return plug, some instructions indicate you may not need to drain below the skimmer/return lines. Always match the method to your pool hardware and product directions.

Step 8: Disconnect, Drain, and Protect the Pump and Filter

For many above-ground pools, winterizing the “plumbing” is less about blowing out long underground lines and more about disconnecting hoses and making sure every component is fully drained.

1. Turn off power to the pump (breaker/switch).
2. Disconnect hoses from skimmer/return/pump/filter and let them drain completely.
3. Remove drain plugs from the pump housing and filter tank so water can drain out.
4. Remove and store small parts (drain plugs, pressure gauge) in a labeled bag.
5. If you have a multiport valve, set it to its winter position (if applicable) so trapped water can escape.
6. Store pump and hoses indoors if possibledry and protected beats “frozen and cracked” every time.

Important detail: some instructions emphasize leaving drain plugs and caps out during winter so any water that finds its way in can still drain.

Step 9: Don’t Drop Chlorine Tablets In and Walk Away

It’s tempting to toss a couple of tabs in and call it a day. Resist. Tablets can sink and sit on the liner, potentially damaging or staining surfaces. Stick with proper closing chemicals designed for winter conditions.

Step 10: Add the Air Pillow (A Shock Absorber for Ice and Snow)

An air pillow helps by creating a “give” point if water freezes and expands, and it can reduce stress on the cover during snow buildup. For many 24-foot round pools, a 4′ x 8′ pillow is commonly recommended.

• Inflate the pillow about 2/3 full (not rock-hard) so it can compress.
• Center it and secure it so it doesn’t drift to the edge like it’s trying to escape.

Step 11: Cover the Pool Like You Mean It

Spread the winter cover over the pool, align it evenly, then secure it using your cover’s cable/winch or fastening system. The cover should be tight enough to resist wind but not so tortured that it’s begging to rip.

Winter reality: water and snow can collect on top of the cover. Excess weight can stress the cover and pool structure. A cover pump is often used to remove standing water and reduce strain.

Also: never try to “help” by breaking ice on the cover. That can tear the cover or damage the liner. Let ice melt naturally, then pump off the water. And don’t let anyone walk on the cover or iceyour pool is not a winter trampoline.

Winter Check-Ins (Low Effort, High Reward)

You’re not done foreveryou’re just done frequently. Every few weeks (or after major weather):

• Remove leaves and debris from the cover.
• Pump off excess water if you use a solid cover and water accumulates.
• Check that the cable/winch and cover edges are still secure.
• Make sure sharp objects (branches, shifting hardware) aren’t rubbing the liner or cover.

Common Mistakes (A.K.A. “How Pools Get Expensive”)

• Closing too early: warmer water encourages algae growth and can reduce chemical effectiveness before winter ends.
• Forgetting to drain equipment: trapped water freezes, expands, and cracks housings.
• Leaving tablets in the pool: can damage liners or stain surfaces.
• Under-securing the cover: wind gets under it, and now you’re hosting a leaf festival.
• Letting water pool on the cover: too much weight can stress the cover and pool components.

Spring Opening Preview (Because You’ll Thank Yourself Later)

A properly winterized pool usually opens with less sludge, fewer stains, and fewer surprise parts you “definitely didn’t lose.” In spring, you’ll reconnect equipment, refill to operating level, restart filtration, and rebalance water. If you closed clean and balanced, spring is mostly chemistrynot chaos.

Real-World Experiences: What Winterizing a 24-Foot Pool Actually Feels Like (And What People Learn the Hard Way)

Winterizing looks straightforward on paper: clean, balance, plug, cover, done. In real life, a 24-foot above-ground pool has a personality. It’s big enough to feel like a “real pool,” but still small enough that you’ll find yourself holding a hose in one hand and a return fitting in the other, wondering how the tiny O-ring you just dropped can possibly be this good at disappearing.

A common first-timer moment is realizing how much stuff your pool has accumulated. You pull out toys, a brush, a vacuum head, maybe a ladder, and suddenly your deck looks like a yard sale for aquatic equipment. The trick most seasoned owners use is simple: make a “drying zone”a towel or tarp where hoses and accessories can drip-dry before going into storage. That one move reduces moldy surprises and keeps spring setup from smelling like a damp basement science project.

Another very real experience: the air pillow. People buy it, inflate it, toss it in, and two days later it’s wedged against the wall like it’s trying to become one with the skimmer. The fix is not complicatedtie it off so it stays centeredbut it’s one of those lessons you learn after you’ve chased it around the pool with a telescoping pole while your neighbor pretends not to watch.

Then there’s the cover. On a 24-foot pool, the cover is large enough that a gust of wind can turn it into a sail for a few seconds. Many owners swear by doing the cover install with at least one helper. Not because you can’t do it alone, but because the cover will happily demonstrate why teamwork exists. The best “experienced-owner” habit is to line the cover up evenly before you start tightening anything. If you tighten the cable/winch while the cover is crooked, it stays crookedlike a picture frame hung by someone who “eyeballs it.”

Water on the cover is another big one. People often assume a little water is harmless. A little is fine; a lot is a problem. The practical learning here is to think in thresholds: if you’re consistently seeing standing water that looks like a kiddie pool on top of your pool cover, it’s time to pump it off. Owners who stay on top of this tend to report fewer cover tears and fewer spring surprises. If you live in a leaf-heavy area, a leaf net over the winter cover can feel like cheatingin the best waybecause it makes cleanup faster and reduces the amount of decomposed leaf “tea” that tries to sneak into spring.

Chemistry has its own reality check. Plenty of people do the “good enough” versionshock, pour in a closing kit, shrug. But the folks who have the easiest spring openings usually do two specific things: they clean thoroughly before closing and they balance pH and alkalinity instead of hoping winter will magically stabilize things. It’s not glamorous, but it’s the difference between opening to “pretty clear water” and opening to “why is it the color of split-pea soup.”

The final lived-experience tip is the one nobody brags about: labeling parts. Drain plugs, pressure gauges, hose clamps, return eyeballs, skimmer faceplate screwsthese tiny pieces have a talent for wandering off. People who throw everything into a labeled zip bag (and stick it in the pump basket or a dedicated bin) tend to open their pools calmly. People who don’t… tend to open their pools while muttering, “It was right here last year.”

If you take anything from the collective experience of above-ground pool owners, let it be this: winterizing a 24-foot pool is not hard, but it rewards a little organization. Clean like you mean it, drain what can freeze, plug what can crack, and cover it like you want it to still exist in spring. Do that, and next season’s opening will feel less like disaster recovery and more like flipping your backyard back to “summer mode.”

Conclusion

Winterizing a 24-foot above-ground pool isn’t about perfectionit’s about preventing the big three: algae explosions, freeze cracks, and cover catastrophes. Close at the right temperature, clean thoroughly, balance your water, protect the skimmer/returns, fully drain equipment, and secure the cover with a sane plan for water removal. That’s how you turn spring opening into a quick refresh instead of a full-blown rescue mission.