Best Pool Closing Kits

Written by Michael Dean
February 20, 2024

pool closing kit with award ribbon

When the summer is fading and you’re getting ready for the winter, closing down your pool is often one of the last things you want to do. But if you have a suitable pool closing kit, closing your pool is easy, and you can rest assured knowing your pool is clean and safe against algae growth throughout the upcoming winter.

There are many factors to consider when purchasing a pool closing kit, and knowing which ones are the best value or quality can be hard. Below, I’ve compiled a list of the five best pool closing kits, including all the details from my research and the factors you should be looking for.

Pool Closing Kits: My Top Picks


In The Swim Pool Winterizing and Closing Chemical Kit

⭐ Best Value Closing Kit

In The Swim Pool Closing Kit

In The Swim makes a great winterization kit that includes all the chemicals you need to close your above ground or inground pool.

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Research Score: 4.8 / 5

  • Chemicals: 5
  • User Friendliness: 5
  • Compatibility: 4
  • Price: 5

Specs:

  • 1 Qt. of Winterizer
  • 1 Qt. of Winter Stain-Away
  • 1 Winter Sorb
  • 1 Winter Pool Floater
  • 2 lb. of Chlorine-Free Shock

What’s Great:

  • Great value product for the price
  • Keeps pool clean all winter by slowly releasing chemicals
  • Sorb keeps the pool’s plumbing clean
  • Chlorine-free

Cons:

  • You can’t use the kit on a pool on a biguanide system
  • It doesn’t ship to Hawaii or Alaska
  • You’ll need to get antifreeze and an air pillow separately (if needed)

Research Notes

The In The Swim pool closing kit has the best value out of all the closing kits we have listed. This kit comes with high-quality winter stain-away, winterized algaecide, pool shock, a time-release pool floater, and a winter sorb. These products will keep your water chemistry intact and fight off algae and other contaminants that may infest your pool while it is in hibernation.

The pool floater is a unique touch. This device slowly releases chlorine-free pool shock into your pool throughout the winter, meaning that your pool will constantly be topped up with oxidizing chemicals. This is an excellent option if you are looking for a quality closing kit for a good price!

Chemicals

In The Swim’s Winterizing Kit includes all the basic chemicals you’ll need to close your pool for the season. The basic package includes 2 pounds of non-chlorine shock, a metal and calcium stain prevention (Diphosphonic Acid), and a potent copper-based algaecide. The chemicals in the “Deluxe” package are enough for a pool of up to 15,000 gallons, but you can upgrade to a larger “Super” winterizing package if you have a bigger pool.

The only downside when it comes to the chemicals is that the winterizing kit doesn’t include antifreeze, but most pool owners won’t need this anyway.

User Friendliness

This pool closing kit is extremely intuitive and simple to use. In The Swim includes clear instructions on how to use the product, making it easy for a pool owner with zero winterizing experience to use. The chemical levels are pre-measured for your pool size, so you don’t have to break out the chemistry equipment or calculator to ensure you get the right measurements.

Make sure you purchase the correct size winterizing kit for your pool or multiple kits. For example, if you have a pool between 15,000 and 35,000 gallons, purchase an In The Swim “Super” Winterizing Kit for a larger pool. If your pool is less than 15,000 gallons, you can purchase the “Deluxe” Winterizing Kit.

Not sure how many gallons are in your pool? Check out my pool volume calculator.

Compatibility

This pool closing kit works with most pools, but unfortunately, it is incompatible with biguanide pools. However, if you have a standard chlorine pool or a saltwater pool, you can use this closing kit. Additionally, the chlorine-free shock and other chemicals can be used on vinyl liners (some harsher forms of chlorine can break down your vinyl liner).

Price

The cost is among the best things about In The Swim’s closing kit. When you factor in everything you get with this kit, it is incredibly budget-friendly, even if you have a larger pool. The “Deluxe” package costs only $45 and has everything you’ll need to winterize a pool smaller than 15,000 gallons. The “Super” package costs $62 and covers everything for a pool up to 35,000 gallons. This price is more than fair. The only downside is that if you live in an especially cold area, you’ll have to buy pool-safe antifreeze separately.

Notes From Other Testers

The In The Swim pool closing kit is one of the highest-rated and most popular closing kits you can buy. With over 14,000 sales on Amazon, this closing kit has maintained a 4.6-star rating out of 5! Users are generally happy with the results, and most open up their pool in the spring without any unpleasant (and green) surprises. Some pool owners claimed that the chemicals in this winterizing kit made balancing in the spring difficult, but as long as you use the right package for your pool size, your chemistry should be okay.


Robelle 3415 Triple-Action Winter Kit

⭐ Best Closing Kit for Inground Pools

Robelle Triple-Action Winter Kit for Swimming Pools
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Research Score: 4.5 / 5

  • Chemicals: 5
  • User Friendliness: 4
  • Compatibility: 5
  • Price: 4

Specs:

  • 1 Qt. of Robelle Winterizer
  • 2 lb. of Robelle Winter Shock
  • 1 Qt. of Robelle Anti-Stain Control

What’s Great:

  • Works well with bigger pools
  • Reasonably priced
  • Includes non-chlorine shock

Limitations & What Needs Improvement:

  • Instructions can be a bit difficult to understand
  • Doesn’t come with a floater, pool pillow, or any other winterizing accessories

Research Notes

Another great choice for a pool closing kit is the Robelle Triple-Action Winter Kit. This closing kit will keep you worry-free throughout the off-season, as the chemicals inside will ensure that you won’t have any algae infestations or worse! This closing kit is easy to use, and the chemicals come in pre-measured quantities, so you won’t have to worry about calculating how much of each winterizing agent to add. Just simply pour them into the pool, and you are ready to go! 

This pool closing down kit comes with your standard pool closing chemicals and a stain remover, which can help clean any stains at the end of the season and at the beginning when opening up for the summer.

Chemicals

The Robelle Triple Action Winterizing Kit comes with all the basic winterizing chemicals you’ll need to lay your pool to rest for the winter. This includes a chlorine-free pool shock, algaecide, and stain prevention chemicals. You can either purchase the 15,000-gallon pool package or the 30,000-gallon pool package, depending on your pool volume. This pool closing kit does not include anti-freeze, so you’ll have to purchase this separately if you live in an extremely cold area.

User Friendliness

This is a relatively user-friendly product. The chemicals come pre-measured for your pool size and ready to pour in the water, and there are not any overly complex measurements needed. That said, the instructions included with this pool closing kit are brief and won’t walk you through all the necessary steps. So, if this is your first time winterizing a pool, you may be a little lost. This is where my full guide for winterizing a pool will come in handy!

Compatibility

This is an excellent product for all pool types, but especially for larger inground pools that need a potent dose of winterizing chemicals before shutting down for the season. This winterizing kit comes in a smaller package for pools less than 15,000 gallons and a larger package (essentially just the same as the normal package but doubled) for pools up to 30,000 gallons. You’ll have to purchase multiple closing kits if your pool is larger than 30,000 gallons. Additionally, the chemicals in the kit are chlorine-free, so you won’t have to worry about them eating into your vinyl liner during the winter. Unfortunately, this is not a suitable option if you have a biguanide pool.

Price

The Robelle Triple-Action pool closing kit is a bit more expensive than the In The Swim option and doesn’t include any other winterizing features besides the standard chemicals. While it is slightly pricer, this closing kit is still reasonably priced and is a good value for winterizing large, inground pools.

Notes From Other Testers

This pool closing kit maintains 4.4 stars out of 5 from more than 800 reviews. So, it is safe to say that most pool owners who used this product to close their pools were happy with the results. Other users stated that the Robelle Triple-Action Kit cleared up their pool before closing, and when it was time to open the pool in the spring, there were no major issues with the water.

On the flip side, some users were not happy with the value of the product, as it is a bit more expensive than other popular options, but doesn’t come with all the bells and whistles.


Doheny’s Ultimate Pool Winterizing and Closing Chemical Kit

⭐ Best Closing Kit for Small Pools

Doheny's Ultimate Pool Winterizing and Closing Chemical Kit
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Research Score: 4.8 / 5

  • Chemicals: 5
  • User Friendliness: 5
  • Compatibility: 5
  • Price: 4

Specs:

  • 1.2 pounds of non-chlorine oxidizing tablets
  • 1 pound of non-chlorine shock
  • 1 pint of “Metal Out” stain remover
  • 1 pint of “Winter Guard” algaecide
  • 1 floating tablet dispenser

What’s Great:

  • Comes in pre-prepped sizes and with a small size valid for pools under 7,000 gallons
  • Comes with both non-chlorine shock and non-chlorine tablets
  • Instructions are easy to follow and thorough

Limitations & What Needs Improvement:

  • A bit expensive for larger pools

Research Notes

If you have a smaller pool, such as an above ground pool or plunge pool, your best bet for winterizing is Doheny’s closing kit. This pool winterizing chemical set comes with everything you’ll need, is easy to use, and comes in small sizes! Most pool supply companies neglect owners of small pools and skip straight to larger kits for pools with 15,000 gallons, but Doheny’s is here for you! Although not the best option for pool owners with larger pools, for small to medium-sized pools, this product is very user-friendly, coming with in-depth instructions for those who may be new to the winterizing process.

Chemicals

Doheny’s Ultimate Pool Winterizing and Closing Chemical Kit comes with a stockpile of winter pool care chemicals. Chlorine-free shock? Check! Algaecide? Check! Metal stain remover? Check! Additionally, this kit comes with chlorine-free, slow-release oxidizing tablets to keep the pool free of contaminants throughout the winter. Honestly, unless you live in an extremely cold climate and require antifreeze, there isn’t much else you’d need to winterize your pool.

User Friendliness

If you are a newbie to winterizing, you don’t need to worry, as Doheny’s does a great job of prepping you for closing your pool with in-depth instructions included in every kit. One of my favorite things about this closing kit is that it comes in a small size for pools that are less than 7,000 gallons. This means that even if you own a tiny plunge pool or above ground pool, you won’t have to buy a more expensive package for a larger pool. Additionally, the Doheny’s Winterizing and Closing Kit comes with pre-measured and packaged chemicals, which makes your job MUCH easier as all you’ll need to do is pour the containers in your pool and wait for the pump to mix them in with your water.

Compatibility

While you can’t use this winterizing kit with biguanide pools, it can be used with most other sanitization methods. So, whether you have a saltwater or a traditional chlorine system, you can close your pool with Doheny’s closing kit. Furthermore, I’ve rated this winterizing kit a 5 out of 5 for compatibility since it is smaller, making it perfect for pools with 7,000 gallons or less (while most other kits start at 15,000 gallons)!

Price

This kit is reasonably priced, costing around the same as most major pool closing kits on the market. The biggest selling point of Doheny’s closing kit is that it comes with a smaller package, so if your pool is less than 7,000 gallons, you’ll save up to $20 since you won’t have to purchase a kit designed for larger pools. That said, if your pool is more than 15,000 gallons, Doheny’s closing kit is a bit on the pricey side, so you may consider opting for the In The Swim option instead.

Notes From Other Testers

Doheny’s Ultimate Pool Winterizing and Closing Chemical Kit is very highly rated and popular among pool owners. This pool winterizing kit has a 4.6 rating out of more than 1,100 Amazon reviews! This means that over 90% of reviewers gave the product at least 4 out of 5 stars! 

Some users have used this product for years and say it works like a charm every single season, allowing them to open up their pool without the anxiety of finding murky green water. However, a few users had issues with their orders coming without a few of the products, but the good news is they could contact the company and get replacement chemicals.


Rx Clear Winter Pool Closing Kits

⭐ Best Chlorine-Based Closing Kit

Rx Clear Winter Pool Closing Kits
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Research Score: 4.3 / 5

  • Chemicals: 5
  • User Friendliness: 4
  • Compatibility: 3
  • Price: 5

Specs:

  • 1 lb. Alkaplus pH powder
  • 1 lb. all-in-one shock
  • 1 lb. winterizing powder

What’s Great:

  • Suitable for up to 45,000 gallons
  • Easy to use
  • Includes clear instructions
  • Includes all chemicals needed to winterize

Limitations & What Needs Improvement:

  • Not compatible with vinyl liners
  • Best not to use for plaster pools

Research Notes

If you’re after a chlorine-based pool closing kit, Rx Clear Winter Pool Closing Kit is a great pick. While chlorine shock is not generally recommended for plaster-based or vinyl liner pools, if you have any other type of pool, this is a great option. You don’t need to purchase any additional chemicals, as everything comes included, making it a great value. The instructions are also easy to follow, making using this kit a seamless process.

Chemicals

All you need in a chlorine-based pool closing kit is included in this Rx product. It has a pH powder, shock, and a winterizing powder that includes algaecide, clarifier, and more. The winterizing chemicals will help make it easier for you to open the pool in the spring or summer. They prevent algae growth, eliminate metals and minerals, and eliminate unwanted oils and grime from your pool water, keeping the pool crystal clear in the coming months. Furthermore, the Premium winter chlorine closing kit includes an additional winter stain-out and two floating dispensers with Borax tablets.

User Friendliness

The Rx Clear winterizing kit is very easy to use, with other users rating it 4.6 out of 5 stars for ease of use. There are 4 sizes of this winterizing kit, so just pick one that fits your pool and follow the clear instructions that come with the product. Note that since this is a chlorine-based product, you must shock your pool a couple of days before adding the winterizing powder.

Compatibility

While the Rx Clear is perfect for all pool sizes, with products for 10,000 gallons to 45,000 gallons, the issue with compatibility lies in the fact that this is a chlorine-based pool closing kit. That means this automatically makes it unsuitable for vinyl pools. And if you have a plaster pool, I would advise against using this product as well.

Price

The Rx Clear kit comes at a very competitive price, especially considering the number of products that come with it. The Premium winterizing kit for up to 45,000 gallons is $63, the winterizing kit for up to 30,000 gallons costs $50, the kit for up to 20,000 gallons is $41, and the kit for up to 10,000 gallons costs $37.

Notes From Other Testers

With more than 1,500 reviews, the Rx Clear winterizing kit is rated an average of 4.5 out of 5 stars, which is no mean feat. Users particularly love that this kit is easy to use, has clear instructions, and is good value for money. However, beware if you have a vinyl liner. You should steer clear of this closing kit!


SeaKlear AquaPill

⭐ Easiest Winterizing Kit to Use

SeaKlear AquaPill AP71 WinterPill Swimming Pool Winterizer Pill
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Research Score: 4.3 / 5

  • Chemicals: 3
  • User Friendliness: 5
  • Compatibility: 4.5
  • Price: 5

Specs:

  • 1 part clarifier
  • 1 part scale inhibitor
  • 1 part stain inhibitor
  • 1 part enzymes

What’s Great:

  • Compatible with all sanitizing systems
  • Compatible with all pool surfaces, including vinyl
  • Incredibly easy to use
  • Good value for money

Limitations & What Needs Improvement:

  • Up to 15,000 gallons only
  • Does not include pool shock, algaecide, or pool-safe antifreeze

Research Notes

If you’re looking for something easy regarding pool winterization, get the SeaKlear AquaPill. Winterizing couldn’t be made easier: simply poke a couple of holes and pop the pill in the water. The winterizing pill will distribute the chemicals throughout the winter months, ensuring protection. While it may not be the most extensive product in terms of chemicals, it is compatible with all sanitizing systems and all pool surfaces. As long as you make sure to shock the pool before you close the pool with the AquaPill, your pool should stay crystal clear and ready for the warmer months.

Chemicals

This is, unfortunately, where the SeaKlear AquaPill falls a little short. This product is an all-in-one formula that contains a clarifier, scale inhibitor, stain inhibitor, and enzymes. What it lacks, however, is a pool shock. Furthermore, it does not include algaecide or pool-safe antifreeze. In terms of pool closing kits, it is a bit lacking on this front. SeaKlear AquaPill is best used in conjunction with other winterizing chemicals, so you may want to use it after shocking your pool for best results.

User Friendliness

All you need to do to use the AquaPill is simply take out the blue piercing tool, insert it into the center hole, and press until you pierce the plastic. Then, pierce two holes on the logo side of the pill using the white pushpin. After piercing the holes, place the AquaPill in the pool. With this product, there is no need to manually dump the chemicals in the pool. Instead, it will float and dispense the formula throughout the entire winter, ensuring your pool is protected throughout the colder months.

Compatibility

The SeaKlear AquaPill is compatible with all types of pools, including vinyl. This winterizing kit is also compatible with all sanitizing systems as well! The only thing lacking is that one pill is only for use up to 15,000 gallons. So, if you have a bigger pool, you’ll need to purchase another pill. For this reason, I have docked off half a point.

Price

At around $25, the AquaPill is honestly one of the cheapest pool closing kits you can get! For such a user-friendly winterizing kit, this product is a steal for sure! While it may not contain all the chemicals you may want to winterize your pool, you’ll simply need to supplement with chemicals you should already have in your storage shed.

Notes From Other Testers

With more than 10,000 reviews, the SeaKlear AquaPill is one of the most popular winterizing kits on the market. It has an average rating of 4.4, and it rates particularly highly for the following categories: easy to install, easy to use, easy to remove, and value for money. As you can see, users love that the AquaPill is incredibly user-friendly and doesn’t require a deep knowledge of pool chemistry. Unfortunately, there are a few complaints that this winterizing kit doesn’t do a thorough job, but as long as you supplement it with other winterizing chemicals, such as a pool shock and algaecide, you should be golden by the time the summer rolls around.


Recap: The Best Pool Closing Kits


My Research Criteria

When I am deciding what the best pool closing kit for a specific pool owner is, I use four main criteria:

  • What chemicals does the kit use?
  • How user-friendly is it?
  • What types of pools is it compatible with?
  • What is the price of the closing kit?

Chemicals

The chemicals a pool closing kit comes with are very important to pay close attention to. Most pool closing kits should come with the standard chemicals used in a chlorine-based swimming pool. If you use biguanides in your swimming pool, look for chlorine-free options that will fit the chemical makeup of your pool.

The standard chemicals you’ll need to adjust before closing your pool for the season are pH, alkalinity, and calcium hardness. You should also make sure your chlorine levels are between 1-3 ppm (parts per million). And finally, you should shock the pool at night a few days before closing it. Sound familiar? These are the exact chemicals and treatments that are available in most pool winterization kits. Some closing kits will also include algaecide, an optional chemical you can add for extra protection against algae growth.

You must also know how the chemicals will interact with other parts of your pool. Certain chemicals (the most notable being chlorine) will interact badly with certain kinds of lining or pool covers (especially ones made of vinyl). Furthermore, if you use biguanides in your swimming pool, some chlorine-free winterizing solutions may react poorly with your specific filtration system.

Chemicals accounted for 30% of the score.

User Friendliness

Some pool closing kits can be confusing to use and are designed for professional pool contractors rather than the average pool owner. So, ensure the pool closing kit has clear instructions on how to use each chemical. Additionally, some pool closing kits will come “ready to go,” meaning that each chemical is already pre-measured for your specific pool size. So, all you need to do is pour it in. In this case, you will obviously need to buy a closing kit designed for your specific pool size. Make sure that the pool closing kit you purchase is made for your pool kit, and ensure you won’t need extensive chemistry knowledge to use it.

User friendliness accounted for 30% of the total score.

Compatibility

It would be super frustrating to purchase a pool closing kit only to find out it is not compatible with your pool. Therefore, you should always ensure that the pool testing kit has enough chemicals for your pool size and the right chemicals for your sanitization system. For example, if you have a chlorine pool, you should get a closing kit for a chlorine system. You should also consider the average low temperatures in your region. If the winter weather regularly drops below freezing and experiences lots of heavy snow, you should look into getting a winterizing kit that also includes an air pillow and pool-safe antifreeze.

Compatibility also matters when it comes to pool size. Because pool closing kits come in pre-measured containers and require you to dump all the contents into your pool rather than measuring them out, you will want to get a kit that is the right size for your pool.

If you cannot find the right size kit, I recommend buying the next size up and following the manufacturer’s instructions for how much of the closing kit chemicals you need to use. You can use my pool volume calculator to determine how many gallons of water are in your pool to measure everything.

Compatibility accounted for 20% of the score.

Price

The final thing I factored in when testing pool closing kits is the price. Most pool closing kits range from $25 to $70, depending on the number of gallons it is designed for, the types of chemicals included, brand recognition, etc. While it is important to get a reputable pool closing kit, you don’t want to spend too much money on one. After all, most closing kits are made of the same chemicals, just packaged differently. The closing kits I tested are a good balance between a fair price and quality.

Price made up 20% of the total product score.

Other Things to Consider

Before deciding on a pool closing kit, here are some additional things to consider.

Does It Add Value by Giving You Extras?

Many of the best pool closing kits will include extra materials to add value to your purchase. For example, small things like a pool float that slowly releases a pool cleaner can help a closing kit stand out against the competition.

Stain removers and metal treating agents are not always necessary to get your pool ready for the winter, but they will increase the chance everything is still functioning and looking pristine when the summer eventually rolls around.

That’s about it for winterizing kits. Also, be sure to read my guide on winter pool care for more off-season tips.

Any questions? Drop me a line; I’m always happy to help.

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