Seasonal Care
The gizzmo is designed to be destroyed
That is the entire idea. Ice expanding in a skimmer has to crush something, and a few dollars of hollow plastic is a much better candidate than a molded-in skimmer body.
Heads up: we earn a commission if you buy through the links on this page, at no extra cost to you. It never decides the ranking — here is how we pick and here is the full disclosure. Prices are checked automatically; last verified October 8, 2026.
Quick picks
Segmented before it is ranked — the right answer depends on which of these you actually are. Tap any row for the full write-up.
The gizzmo and plug set
Threaded to your skimmer, and long enough to reach below the water line inside it. Both dimensions matter and only one is usually on the listing photograph.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 | No image Skimmer Gizzmo and Winter Plugs A hollow tube that screws into the skimmer and crushes instead of the skimmer when water freezes. It is a sacrificial part, and that is precisely the point. | Stopping ice cracking the skimmerSeveral seasons | 8.8out of 10 |
For lines you cannot clear
Plugs seal the openings; antifreeze handles what is still inside the pipe. They are complementary, not alternatives.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 | No image Pool Antifreeze (Propylene Glycol) Non-toxic propylene glycol poured into lines that will not blow out completely. It protects pipe, not water, and it is not the same chemical as the antifreeze in your car. | Plumbing you cannot fully drainOne honest season | 8.5out of 10 |
What it is protecting alongside
The chemistry side of the same afternoon. Plugs protect the hardware; the kit protects the water.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 | No image Pool Winterizing / Closing Chemical Kit A box with the closing chemicals pre-matched to a pool size. Worth the small premium the first year purely because the failure mode of buying separately is missing one thing on the day. | A first close, when you do not know what you needOne honest season | 8.0out of 10 |
The short version
- It is a sacrificial part. The gizzmo crushes so the skimmer does not, and a crushed one has done its job.
- A cracked skimmer is not repairable on most above-ground pools — it is molded into the wall.
- Two dimensions matter: the thread size and the length. Most people check one.
- Every opening needs its own plug, and returns take expansion plugs rather than threaded ones.
Why a skimmer cracks
Water expands as it freezes. In an open pool that expansion has somewhere to go — upward. Inside a skimmer, which is a rigid box with water sitting in it, it does not: the ice pushes outward against the walls of the skimmer with genuinely enormous force, and the skimmer is the thing that gives.
On an above-ground pool that is a bad failure, because the skimmer is usually part of the wall assembly rather than a separate serviceable unit. Our skimmer guide covers the hardware; the relevant point here is that replacing one is a job and finding a cracked one in April is a very bad start to the season.
Getting the size right
| Dimension | Common values | If wrong |
|---|---|---|
| Thread | 1.5 in and 2 in threaded skimmers | It will not screw in and does nothing |
| Length | 9 in regular, 16 in for deeper skimmers | Too short leaves water above it, unprotected |
| Return plugs | Expansion type, sized to the opening | Water re-enters the line and freezes |
| Blowout valve | On some longer gizzmos | Useful if you are blowing lines out |
Length is the one people miss. A gizzmo protects the water it displaces, and if your skimmer holds more water than a 9-inch tube reaches into, the water above it is doing exactly what you were trying to prevent. Measure the depth of the skimmer body before ordering.
The other thing worth knowing is that returns are usually not threaded. Those take expansion plugs — a rubber bung with a wing nut that spreads it against the wall of the opening — rather than a screw-in gizzmo. A closing kit needs both types.
Fitting them, which takes five minutes
Lower the water to the manufacturer's winter level first
Below the skimmer mouth. Your pool's own manual publishes the level; follow that rather than a general rule, because it differs by pool type.Take the skimmer basket out
It goes in the shed with the pump. A basket left in freezes into whatever is around it and cracks.Screw the gizzmo in hand-tight
No tools, no tape, no force. It only needs to seal against water re-entering, and over-tightening a thin plastic tube into a plastic thread is how you crack the skimmer in September instead of January.Plug every other opening
Returns, cleaner ports, anything below the water line. Expansion plugs for unthreaded openings, tightened until they seal and no further.Write it on the cover list
A gizzmo left in at opening blocks the skimmer completely, and it is a genuinely confusing fault to diagnose. Our spring shopping list is the place to note it.
Where it ranks in the closing kit
Very near the top, on a cost-to-benefit basis. A few dollars of plastic against a skimmer molded into the pool wall is the best trade in the entire seasonal hub, and it takes five minutes.
The full order, for a pool left standing over winter: cover and air pillow first, plugs second, pump brought indoors third, and antifreeze fourth if you have plumbing the first three do not cover. Our closing kit guide is the complete list and our cost of a bad close guide prices what each one is insuring against.
What we are scoring
We have not tested these and do not claim to. The scores reflect published specifications — thread size, length, material and whether a blowout valve is fitted — against an above-ground pool left standing over winter. Our methodology page explains how our scoring works.
The picks, in full
Scores are our own reading of published specifications. They are not test results — we have not tested these products and we do not claim to.
Pick #1 · Stopping ice cracking the skimmer
Skimmer Gizzmo and Winter Plugs
Various
A hollow tube that screws into the skimmer and crushes instead of the skimmer when water freezes. It is a sacrificial part, and that is precisely the point.
Key specs
- Skimmer gizzmo
- 9 in for short skimmers; 16 in for deeper
- Thread
- 1.5 in and 2 in threaded skimmer fittings
- Function
- Absorbs the expansion of freezing water
- Return plugs
- Expansion plugs for unthreaded return openings
- Fits
- Above-ground and inground skimmers
- Life
- Replace any gizzmo that has crushed — it did its job
How it scoresour reading of published specs, not a test result
- Protection
- 9.0
- Fit
- 7.0
- Ease
- 9.5
- Build
- 7.5
- Value
- 9.5
Overall 8.8 / 10
What works
- Cheapest possible insurance against a cracked skimmer, which is not a repairable part
- Screws in by hand — no tools, no plumbing knowledge, two minutes
- Expansion plugs seal returns so water cannot re-enter and freeze in the line
- Reusable season after season unless it has actually crushed
What doesn't
- Thread sizes vary and a gizzmo that does not thread in does nothing
- Short and long versions exist and the wrong length leaves the skimmer exposed
- Easy to forget at opening, and a gizzmo left in blocks the skimmer
- Pointless on a pool that is fully dismantled and stored
Skip it if: Protecting anything other than the fitting it is in. Every opening needs its own plug, and the pump and hoses are a separate job.
What it costs to run: A few dollars against a skimmer body that is molded into the pool wall. On any pool left standing over winter, this is the highest-return item in the closing kit.
Several seasons: Buy-once. Built and warranted to come back out of the box for a few years, if you store it properly.
Specs from: Skimmer gizzmo for above-ground pools — Amazon listing
Pick #2 · Plumbing you cannot fully drain
Pool Antifreeze (Propylene Glycol)
Various
Non-toxic propylene glycol poured into lines that will not blow out completely. It protects pipe, not water, and it is not the same chemical as the antifreeze in your car.
Key specs
- Active
- Propylene glycol — never ethylene glycol
- Protection
- Burst protection quoted to about -50°F
- Dose
- About 1 gal per 10 ft of 1.5 in pipe
- Spring
- Safe to release into the pool at opening
- Format
- Sold by the gallon, often in fours
- Not for
- The pool water itself — this goes in plumbing only
How it scoresour reading of published specs, not a test result
- Protection
- 8.5
- Ease
- 8.5
- Safety
- 9.0
- Cost per season
- 9.0
- Value
- 8.5
Overall 8.5 / 10
What works
- Non-toxic and swimmer-safe, so it can be flushed into the pool in spring
- Protects lines that cannot be blown out completely, which is most home setups
- Cheap against a cracked pump housing or a split return line
- Also protects against rust and corrosion in the line over winter
What doesn't
- Does nothing for the pool water and is not meant to go in it over winter
- Automotive antifreeze looks similar and is toxic — the labels matter
- On a fully dismantled seasonal pool there is nothing to protect
- Dosing by pipe length means measuring your own runs
Skip it if: Being a substitute for draining. Blow the lines out first; antifreeze is insurance on what you could not clear, not an alternative to clearing it.
What it costs to run: One or two gallons on a typical above-ground plumbing run, once a year. Against the replacement pump our replacement parts guide prices, it is not a close call.
One honest season: The cheapest setup that genuinely works for a season of real swimming. Nothing spare, nothing missing.
Specs from: CPDI Champion swimming pool antifreeze — Amazon listing, Pool antifreeze — current Amazon category listing
Pick #3 · A first close, when you do not know what you need
Pool Winterizing / Closing Chemical Kit
Various
A box with the closing chemicals pre-matched to a pool size. Worth the small premium the first year purely because the failure mode of buying separately is missing one thing on the day.
Key specs
- Typically contains
- Winter algaecide, shock or oxidizer, and a stain/scale preventer
- Sized by
- Pool volume in gallons — buy to your actual number
- Timing
- Applied at closing, with the pump running, before covering
How it scoresour reading of published specs, not a test result
- Retention
- 8.0
- Durability
- 8.0
- Handling
- 9.0
- Running cost
- 7.5
- Value
- 8.0
Overall 8.0 / 10
What works
- Pre-matched to a volume, so the dosing decision is made for you
- Nothing missing on closing day, which is the actual value
- Polyquat-based kits avoid the liner-staining risk of copper algaecides
What doesn't
- Costs more than the same chemicals bought individually
- Kits are sized in broad volume bands, so you may be over-treating
- Some kits include products a small seasonal pool genuinely does not need
Skip it if: Year two onward. Once you know what your water actually does over a winter, buying the two things you need is cheaper.
What it costs to run: Pay the premium in year one and buy separately afterward. The kit's real value is that it prevents the expensive mistake of closing a pool with something missing.
One honest season: The cheapest setup that genuinely works for a season of real swimming. Nothing spare, nothing missing.
Questions people actually ask
What does a pool gizzmo do?
What size gizzmo do I need?
Do I need plugs for the return lines too?
What happens if I leave the gizzmo in at opening?
Sources
Read next
- Closing, covering and opening againWinterizing, covers and spring opening - the four weeks of the year that decide whether you own a pool next summer.
- How to winterize an above-ground poolThe correct closing sequence, the freeze damage that ends pools, and why a cracked pump housing is entirely preventable.
- Pool antifreeze protects pipe, not waterWhat pool antifreeze actually does, why it is propylene glycol rather than the automotive kind, how much to use, and when you do not need it at all.
- Pool closing kits: buy one the first year, then stopWhat is in a closing kit, whether the bundle premium is justified, and how to buy separately once you know your water.
- Winterizing kits: convenience, correctly sized, or a wasteWhat is inside a winterizing kit, how to size one to your gallons, and the items every kit leaves out.
- A freeze is forecast and the pool is still openWhat to protect first when a cold snap arrives before closing day, why the equipment is at risk before the pool is, and when to just close early.
- Opening an above-ground pool in springThe spring sequence in order, why cloudy water at opening is normal, and the two timing errors that cause green openings.
- The bill a bad close sends you in AprilThe spring bill produced by a bad autumn close, priced line by line, and the three cheap items that prevent nearly all of it.
- The skimmer is the cheapest part of the system and the one that stops itHow a skimmer actually works, the water level it needs, and the three silent faults that get blamed on the pump.