pool cover rolled up above pool

Dive into Winter: A Comprehensive Guide to Pool Closing Chemicals

As winter approaches, pool owners know that closing their swimming pools is a necessary but often complicated task. This guide will reveal the intricacies of pool chemicals needed for a secure winter closure and explore why professional services like those offered by Net Positive Pools can make all the difference.

Essential Pool Closing Chemicals & Steps 

As the leaves turn orange and temperatures drop, many pool owners face the daunting task of preparing their swimming pools for winter. While it might seem as simple as throwing a pool cover on and calling it a day, the process involves a scientific approach that shouldn’t be overlooked. At the heart of this task are pool closing chemicals that help protect your investment throughout the winter months.


  1. Chlorine Shock: Before you start the closing process, it’s crucial to shock your pool with chlorine. This helps eliminate any remaining bacteria or organic contaminants that might linger in the water during the off-season. 
  2. Algaecides: Algae can be a persistent problem in pools, even when they’re not in use. Adding an algaecide to the water before closing it down can help prevent algae growth. Choose a winterizing algaecide designed to work effectively during the colder months. It’s essential to select the right type of algaecide based on your pool’s needs and size.
  3. pH Balancers: Proper pH balance is essential for preserving the integrity of your pool’s equipment and surfaces. Before adding any closing chemicals, ensure that your pool’s pH levels are within the recommended range. If necessary, make adjustments using pH increasers or decreasers. Balanced water chemistry will help prevent corrosion and scaling during the off-season.
  4. Stain and Scale Control: Minerals and metals in pool water can sometimes lead to staining and scaling on the pool’s surfaces. Using a stain and scale control chemical before closing the pool can help prevent these issues. This is particularly important if your pool has a history of such problems or if you’re in an area with hard water.
  5. Cover Cleaner: Preparing the Pool Cover: The pool cover plays a vital role in protecting your pool during the winter. Before covering the pool, use a cover cleaner to ensure that the cover is free from debris, dirt, and contaminants. This step prevents any unwanted materials from seeping into the pool water and causing potential issues.
  6. Water Level Management: Prevent Freezing Damage: As you prepare to close your pool, consider lowering the water level slightly. This helps prevent potential damage from freezing and thawing during the winter months. Consult your pool’s manufacturer guidelines or a professional to determine the appropriate water level adjustment for your specific pool type.

The Benefits of Proper Pool Closing 

If the science behind pool chemicals is not meticulously understood and applied, you could be welcoming a host of problems. The wrong combination of chemicals can lead to scale build-up, create a breeding ground for organic contaminants, and damage the pool surfaces. This underscores the importance of precise measurements and the correct use of a chemical kit specifically designed for pool closing.

1. Prevention of Damage: Shielding Against Harsh Elements

As the temperatures drop, your pool becomes vulnerable to the harsh elements of winter. Freezing temperatures can wreak havoc on your pool’s plumbing, equipment, and surfaces. By closing your pool correctly, you create a protective barrier that shields it from freezing water and potential damage. Without proper winterization, frozen water can expand within the plumbing lines, leading to costly cracks and leaks that require extensive repairs come spring.

2. Water Quality Preservation: Avoiding Contamination and Algae Growth

Leaving your pool untreated and exposed during the winter months can lead to a host of water quality issues. Contaminants, debris, and organic matter can accumulate in the water, creating a breeding ground for bacteria and algae. When spring arrives, you’ll be faced with a time-consuming and often frustrating battle to restore your pool’s water to a clear and healthy state. Properly closing your pool with the right chemicals helps prevent these issues and ensures a smoother opening when the warmer weather returns.

3. Equipment Longevity: Extending the Lifespan of Pool Components

Your pool’s equipment, from the pump and filter to the heater and chlorinator, represents a significant investment. By properly closing your pool, you extend the lifespan of these components. Draining water from the equipment and plumbing lines prevents freezing-induced cracks while using appropriate chemicals prevents corrosion and scaling that can damage critical parts over time. Taking care of your equipment during the offseason means you’ll be able to enjoy it for years to come without the need for premature replacements.

4. Cost Savings: Reducing Repairs and Maintenance Expenses

It’s no secret that pool maintenance and repairs can be costly. However, the expenses associated with improper pool closing can far outweigh the investment of time and resources required for proper winterization. By avoiding issues like frozen pipes, cracked surfaces, and damaged equipment, you save yourself the headache and financial burden of major repairs that could have been prevented with a little foresight and care.

5. Convenience: Ensuring a Smooth Spring Reopening

Imagine the anticipation of the first warm days of spring, only to find that your pool is in disarray due to improper closing. A pool that’s been properly closed will require minimal effort to get it ready for the swimming season. On the other hand, neglecting proper closing could lead to weeks of troubleshooting, cleaning, and balancing chemicals before you can enjoy your pool once again. The convenience of a smooth spring reopening is reason enough to invest the time and effort into proper pool closing.

pool closing chemicals layed out in front of pool

The Importance of Accurate Measurements

Chemical balancing on your own can feel overwhelming and you may be wondering if you’re up to the task. And for a good reason! Measuring chemicals is not something you can afford to get wrong, especially when the health and longevity of your swimming pool are at stake.

Consequences of Incorrect Measurements

What if you measure the chemicals incorrectly? Too much chlorine shock, for instance, can drastically alter the water chemistry and bleach your pool surfaces. On the other hand, too little may fail to eliminate harmful bacteria and organic contaminants. Incorrect measurements can also lead to imbalanced water levels and an uncomfortable pH, making your pool susceptible to algae outbreaks and scale build-up.

Accurate Measurements and Equipment Longevity

Accurate chemical measurements go beyond the immediate winter months; they have a long-term impact on your pool equipment and surfaces. Imbalanced chemical levels can corrode your pool pump, filters, and other equipment, leading to expensive repairs or replacements. Imagine going to open your pool in the spring only to find that your sand filter is damaged or that your pool surfaces have deteriorated due to poor chemical balance.

pool cover on pool in winter

DIY vs Professional Pool Closing – Why Choose Net Positive Pools

Going DIY for pool maintenance might seem tempting, especially with the abundance of how-to videos and chemical kits available. However, this path can be time-consuming and fraught with potential errors. You’re not just balancing water chemistry; you’re also managing the water level, temperature, and even the drain plug positions, among other tasks. These factors are crucial to ensure your pool cover and equipment last through the winter.

The Net Positive Pools Advantage

Enter Net Positive Pools, your one-stop shop for all pool-related needs, including cleaning, maintenance, and even automation remodeling. With multiple locations, we are well-equipped to serve your local community and surrounding areas. Our team brings a blend of expertise and manufacturer support, guaranteeing effective and efficient service.

Long-term Savings

Though it might seem cost-effective to manage your pool yourself initially, the long-term costs of potential mistakes can be steep. Imbalanced chemicals can lead to damaged pool surfaces, and equipment, and even pose health risks. By choosing Net Positive Pools, you’re investing in peace of mind, knowing that trained professionals are maintaining your pool. This not only saves you time but also translates into long-term financial savings, safeguarding your investment for years to come.

pool cover being rolled out over pool

Trust Our Professional Services for Pool Closing

Winterizing your pool may seem like a daunting task, but with the right knowledge and tools it doesn’t have to be. Net Positive Pools is committed to making this process as smooth as possible for pool owners in Huntersville, NC, Greenville, SC, Statesville, NC, and York County, SC.

Contact us today to learn more about our Weekly Pool Maintenance Program and winterizing services.