Best Winterize Pool Chemical Kit for 2021 - Backyard Boss
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Best Winterize Pool Chemical Kit for 2021

Closing your beautiful pool for the winter can be difficult, especially if it’s your first time doing it! There’s a lot of pressure in getting it right and avoiding costly pool dirt, algae growth, grime, and damage from the winter freeze. To prepare for the frost, you need a reliable winterizing pool kit to keep your pool safe and clear for when the temperature drops until you open it next year. The perfect kit is out there, and here are our top five recommendations on the best winterize pool chemical kit for your home!

Backyard Boss Top 5 Best Winterize Pool Chemical Kit for 2021

In The Swim Pool Winterizing And Closing Chemical Kit - Best Winterize Pool Chemical Kit for 2021In The Swim Pool Winterizing And Closing Chemical Kit
  • Capacity: up to 7,500 gal.
  • Item Weight: 11.24 Pounds
  • Formula: Chlorine-Free
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BioGuard Arctic Blue Winter Closing Kit - Best Winterize Pool Chemical Kit for 2021BioGuard Arctic Blue Winter Closing Kit
  • Capacity: up to 24,000 gal.
  • Item Weight: 7 Pounds
  • Formula: Chlorine-Based
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Rx Clear Winter Pool Closing Kit - Best Winterize Pool Chemical Kit for 2021Rx Clear Winter Pool Closing Kit
  • Capacity: up to 20,000 gal.
  • Item Weight: Undisclosed
  • Formula: Chlorine-Based
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Robelle Triple-Action Winter Kit - Best Winterize Pool Chemical Kit for 2021Robelle Triple-Action Winter Kit
  • Capacity: up to 15,000 gal.
  • Item Weight: 7 Pounds
  • Formula: Chlorine-Free
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Qualco Pool Closing Chemical Kit - Best Winterize Pool Chemical Kit for 2021Qualco Pool Closing Chemical Kit
  • Capacity: up to 30,000 gal.
  • Item Weight: 12.9 Pounds
  • Formula: Chlorine-Free
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Why You Can Trust Us

We’ve been in the pool game for quite some time now, and we know that winterizing your pool can be a struggle without the right chemical kit. To lessen your hassle, we’ve done the hard work for you and conducted thorough research to find the best product out today.

Not only did we do research, but we also made sure to consult other pool owners and used their experiences to create a definitive list of the best pool winterizing kits. As a bonus, we’ve also included additional pool winterizing info that can help you close your beautiful pool easier.

Best For Small Pools

In The Swim Pool Winterizing And Closing Chemical Kit
    This comes with a winter sorb pool floater for unbelievably clear water on pool surfaces.



Why We Like It: This In The Swim basic closing kit can close pools up to a 7,500-gallon capacity. 

It includes a winterizer, pool shock, stain preventer, winter sorb, and a winter pool floater. What makes this non-chlorine kit stand out is its winter sorb and floater, which help soak up pool contaminants in the off-season and slowly oxidizes your pool throughout the off-season. Not only will this winterize your pool to prevent freeze damage, but this also keeps it safe and clear for an easy spring opening.

Who Should Buy It: This would be great for those who want to level up their pool game and pick a comprehensive winter pool chemicals kit.

Best For Large Pools

BioGuard Arctic Blue Winter Closing Kit
    No-fuss closing kit that keeps your pool crystal clear through the winter.



Why We Like It: This BioGuard closing kit is enough for pools that hold up to 24,000 gallons of water level and only need two products— the Arctic Blue Shock and Algae Protector! 

The Arctic Blue Shock is a chlorine-based formula that acts as a clarifier and oxidizer to shock your pool for the winter. Its companion is the Algae Protector, which prevents the growth and build-up of all types of algae, keeping your pool crystal clear while it’s closed. Both of these are compatible with all pool types and make it easy to maintain your pool throughout the off-season.

Who Should Buy It: This is perfect for those who don’t want to use many products when winterizing their large pool.

Best For Above-Ground Pools

Rx Clear Winter Pool Closing Kit
    These non-corrosive chemicals are diluted in a bucket and easily added to tall pools.



Why We Like It: The Rx closing kit is easy to use and great for pools that hold up to 20,000 gallons. 

You’ll receive two pounds each of their Alkaplus pH Powder, All-in-One Shock X-Tram, and Winterizing Powder. This kit focuses on keeping your pool balanced through the off-season and prevents any stains on your above-ground pools. It also suppresses algae and grease build-up and protects your metal pool components from corrosion.

Who Should Buy It: This would be fantastic for above-ground pool owners with lots of metal fixtures.

Best Chlorine-Free

Robelle Triple-Action Winter Kit
    This kit is made without chlorine and keeps your pool odor and contaminant-free during the off-season.



Why We Like It: This Robelle winterizing chemical kit is meant for pools with up to a 15,000-gallon capacity and has three components: a quart of Winterizer, two pounds of Winter Shock, and a quart of Anti-Stain Control.

It’s a zero-hassle 3-piece pool winterizing kit that contains no chlorine, keeping your pool odorless and clear. It’s a great pool closing kit to use, no matter what your pool is made of. For best results, use this with a tight pool cover to prevent contaminants from entering the water.

Who Should Buy It: This would be wonderful for people sensitive to chlorine and pool odors.

Best For Vinyl-Lined Pools

Qualco Pool Closing Chemical Kit
    This 3-piece pool winterizing kit has a chlorine-free formula that’s sure to prevent any liner damage.



Why We Like It: The Qualco winterize chemical kit is a chlorine-free set that comes with two pounds of winterizing powder, two quarts of winterizing liquid, and two quarts of a winter stain preventer, made for pools up to a 30,000-gallon capacity. 

The winter pool chemicals in this pool closing kit are amazing for vinyl-lined pools. Despite having strong water clearing abilities, this neither stains your liner nor bleaches it when left in for the winter season. It’s a wonderful way to preserve new vinyl pool lining while it’s closed.

Who Should Buy It: This is the smart choice for those who want an effective winterizing kit that won’t affect their pool lining.

Why You Need To Winterize Your Pool

Above ground pool with deck
Image credit: Canva

Over winter, everyone’s main concern is getting as warm as possible. It usually makes your beautiful pool useless for the season! Even if your pool isn’t at risk of freezing, it’s important to properly close your pool for the winter to avoid algae, dirt build-up, and costly damage instead of just letting it be. A pool that hasn’t been correctly winterized is a huge hassle that could even pose health risks if it hosts dangerous bacteria. Winterizing your pool means protecting your pool investments and keeping it clean and ready for next year’s swim days.

What To Keep In Mind Before Picking A Winterize Pool Chemical Kit

swimming pool near green trees
Image Credit: Trev Morris via Unsplash

Since the perfect kit depends on your pool, here are a few considerations before getting a winterizing pool chemical kit.


A kit can come with various components and chemical formulas that serve different purposes. A pool closing kit can include balancers, pool shocks, winter algaecide, stain preventers, or non-toxic pool antifreeze formulas that are all specially made for winter. Kits won’t always come with all of these, and it’s important to read the label instructions and check if a pool winterization kit has the items you want.

Chlorine vs Non-Chlorine

Choosing between chlorine-based winter kits and non-chlorine formulas is up to your preference. Each has pros and cons, especially when leaving it to soak in your water for the off-season. If chlorine-based formulas are a dealbreaker, check your kit’s ingredients and chlorine level before purchasing it.

Pool Type

Winterizing an above-ground swimming pool is different from closing an inground pool, and you need the correct type of kit that’s appropriate for your pool. Additionally, what you use to sanitize your pool needs to be considered too. If a kit isn’t compatible with your pool, it’s better to find an alternative with superior protection.

Pool Size

Winterizing chemicals are sold in kits for convenience and have been pre-measured according to your pool size by the gallon. You need a kit that can winterize the water in your pool and, if your preferred kit is smaller than what you need, you can simply buy multiples of it. Be sure to read the product description and know the product dimensions to get the correct amount of winter chemical kits for your pool.


Above-ground pool covered with snow
Image credit: Canva

When do I start closing my pool for the winter?

You need to start with closing your swimming pool once during autumn once the water temperature drops below 60ºF. To start, take a week to balance and prepare it for winterizes. After achieving water balance, be sure to study your kit well to have a better time frame of how long it’ll take until you can officially close your pool.

Does my above-ground swimming pool need an air pillow?

Even the best above-ground pools need to be treated carefully and attentively. If you’re wondering how to winterize an above-ground swimming pool, you should pay special attention to air pillows! An air pillow is secured to the center of a pool and prevents its cover from touching the water. Additionally, if your pool freezes without this pillow, the ice can expand and strain your pool walls. With this in place, it helps absorb this expansion instead. We recommend the Blue Wave Air Pillow for Above Ground Pool.

Can I leave my pool alone after winterizing it?

No. As preventative maintenance, it’s best to routinely check in on your pool during the winter to keep the water clean. Even with safety covers and winter chemicals, it’s important to regularly check for cloudy water, clear leftover debris, and monitor your pool for added protection against algae. Although it requires less upkeep this season, winter maintenance will help conserve its condition until your pool opens.

How We Picked

We found our five recommendations after a strict research process. We started with an extensive market analysis on the different winterize pool chemical kits available. After gathering our data and noting those with potential, we turned to experts and casual pool owners for their experiences.

It helped us pay better attention to kits with lots of joy, enthusiasm, and success. Finally, we used first-hand knowledge of each kit for a fuller understanding of their abilities. In the end, there’s no doubt that any of these kits can be a huge help in closing your pool for the winter!

Our Top Pick of the Best Winterize Pool Chemical Kit for 2021

If we had to choose, our favorite from the bunch would have to be the In The Swim Pool Winterizing And Closing Chemical Kit. This kit may be for smaller pools, but it has fantastic components that go beyond any other kits! That said, those extra items aren’t necessary for a successful winter closing. 

We’re all too aware of this kit’s limits and understand that other kits may be better for your needs. Luckily, any of the kits chosen from this list is sure to give you a smooth time closing your pool for winter and opening it next year!