Step-by-Step Guide: Successfully Winterizing & Closing Your Pool

As summer fades and autumn leaves start to fall, it’s time to think about closing your pool for the season. But where do you start? The process can seem daunting, but with the right guidance, it’s easier than you might think.

Key Takeaways

  • The process of closing a pool for the season has 5 key steps, including assessing your pool, cleaning and preparing it, winterizing pool equipment, adding pool chemicals and winterizing products, and putting on a cover.
  • Assessing the pool includes checking water balance and chemistry, as well as inspecting the pool equipment and accessories. Ideal water chemistry ranges include a pH level of 7.2-7.6, alkalinity of 100-150 ppm, and calcium hardness between 200-400 ppm for a plaster pool and 175-225 ppm for a vinyl pool.
  • The cleaning phase involves removing debris and algae and adjusting the water level. Do not drain your pool completely; instead, lower the water level to around 4-6 inches below the pool skimmer to encourage structural integrity.
  • When winterizing the pool equipment, ensure that filters and pumps are disconnected, cleaned, and stored safely indoors. Heaters and other delicate components must also be drained and stored properly.
  • Adding appropriate chemicals and winterizing products helps to maintain the pool throughout the winter season. These include using a chlorine-free shock, an algaecide, an anti-stain treatment, and a winterizing closing powder or pill.
  • It is critical to secure a high-quality pool cover that is both resilient to harsh winter conditions and efficient at blocking out contaminants. Mesh safety covers and solid covers are recommended, with the latter requiring removal before weather turns warm to avoid algae bloom. The cover should be secured properly with water bags, pool cover weights, or winter cover clips.

Assessing Your Pool Before Closing

As the summer sun bids adieu and the fall foliage starts becoming evident, it’s time to initiate the process of closing your pool. Securing your pool for the cooler months creates an assurance of a trouble-free opening once the warmer season returns. The first step in this process involves rigorous assessment of your pool. This assessment begins with checking the water balance and chemistry and extends to inspecting the pool equipment and accessories.

Checking Water Balance and Chemistry

Reviewing the chemical equilibrium of pool water is an integral part of the assessment. This step ensures your pool remains safe and clean until next season’s opening. Initially, test for pH levels, a measure of your pool’s acidity or alkalinity. An optimal pH level ranges from 7.2 to 7.6. Next, assess the alkalinity; a reading of 100 to 150 parts per million (ppm) is viewed as ideal. Finally, check the calcium hardness. Maintaining a range of 200 to 400 ppm is recommended for a plaster pool and 175 to 225 ppm for a vinyl pool.

Additionally, monitoring the level of chlorine in your pool plays an essential role. The concentration of free chlorine should not exceed 3 ppm, while the total chlorine level should remain under 4 ppm. Measuring these chemical levels helps maintain the balance necessary for preserving your pool during the closure.

Inspecting Pool Equipment and Accessories

Another critical element in assessing your pool involves inspecting the necessary equipment. This step safeguards the functionality and longevity of the accessories meant for ensuring smooth pool operation.

Begin by examining the pool pump, which aids in maintaining water circulation. Ensure it’s in good working condition and shows no signs of malfunctioning. An example would be strange noises emitting from the pump. Similarly, scrutinize the pool filter, a device responsible for keeping the water clean. It shouldn’t exhibit any blocks that can harm its efficacy. Lastly, look over the pool heater, if there’s one present. The heater should work efficiently without any clear signs of wear and tear.

Moreover, checking the physical state of pool accessories like ladders, diving boards, and slides also proves beneficial. All of them need to be robust and sturdy, with no signs of damage.

A thorough assessment of water chemistry and pool equipment effectively streamlines the pool closing process. It paves the way for the next steps, thereby assuring optimum care of your pool during the off-season.

Cleaning and Preparing the Pool

Post initial assessment, the cleaning and preparation phase kicks in, taking pool preservation to the next phase. Here, you’ll focus on removing debris and algae, as well as adjusting the water level.

Removing Debris and Algae

A clean pool enhances the success of winterization efforts. Start by skimming off leaves, twigs, and other debris floating on the pool’s surface. Once you’ve garnered these surface-level impurities, turn your attention to the pool floor. Employ a pool vacuum, ideally an automatic one, to expunge dirt and debris that has sunk to the bottom.

Remember, algae will be your greatest adversary during this process. While manual methods such as scrubbing can work, consider enlisting pool algaecides for a more effectual approach. A single dose typically rids your pool of these unwanted organisms and leaves it sparkling clean.

Lowering the Water Level Appropriately

Next up, managing your pool’s water level. Contrary to popular belief, draining your pool completely is far from advisable. Full drainage triggers pressure imbalance, leading to potential pool rise or even structural damage. Instead, aim for a drop in water level to around 4-6 inches below the pool skimmer, sufficient to shield against freezing whilst ensuring structural integrity.

Remember, once the level is aptly lowered, do make a point to plug the skimmers. This tactic prohibits pool water from filtering back in as well as stops debris from flowing into the pipes. Moreover, disconnect your hose from the pool skimmer, a step that circumvents water from infiltrating the pool lines during winter.

In a nutshell, be meticulous in your cleaning and water level adjustments; these strides directly impact the smooth shutdown of your pool during off-season.

Winterizing Pool Equipment

After successfully cleaning your pool and adjusting its water level, it’s time to turn your focus towards the equipment responsible for keeping it running smoothly throughout the summer. Your pool equipment includes filters, pumps, heaters, and other delicate components which need proper care as winter approaches. Let’s guide you through the process:

Managing Filters and Pumps

Given their central role in maintaining water purity and circulation, filters and pumps must be winterized appropriately. It’s recommended to run the pool pump for a full cycle to ensure all the water is circulated from the pool into the filtration system.

Next, any debris that’s been caught by the basket should be removed thoroughly. You’ll spot the basket within your pool pump. After it’s spotless, consider disconnecting your pump and filter system. It is a crucial step in prevention against water damage caused by an unanticipated freeze. Reassemble smaller components indoors in a dry and safe place.

As for the filters, backwash them primarily, followed by a chemical cleaning. In the case of cartridge filters, remove and clean the cartridges, and consider replacing them if they’re worn out. After cleaning, leave the valves on the filter system open to avoid any potential ice damage.

Preparing Heaters and Other Delicate Components

Heating equipment, too, possesses a significant risk of freeze damage if neglected. Ensure to drain all water from the heater exchanger by removing any drain plugs available. Leave them out during the winter months.

Light fixtures and other delicate elements need special attention as well. Remove the underwater light fixture, dry it, and store it in a safe place. Components such as chlorine feeders, check valves, and flow meters can be removed for storage indoors.

By properly managing your pool equipment, you can save relatively high repair costs due to preventable damage. Remember, careful and thorough winterizing ensures your pool’s smooth operation when the warmer weather returns.

Adding Pool Chemicals and Winterizing Products

Following our discussion on testing water levels and managing pool equipment, the next crucial stage involves adding suitable chemicals and winterizing products. This step not only maintains optimal pool condition throughout the chilling season but also simplifies your pool reopening tasks when warmer weather returns.

Choosing the Right Winter Chemicals

Identifying proper winter chemicals constitutes the first phase in this stage. Typically, your pool requires a series of specific substances for winterization including an algaecide, a chlorine shock, an anti-stain treatment to prevent metal and mineral stains, and a winterizing closing powder or pill.

Use a chlorine-free type of shock on closing day. It eliminates contaminants without affecting the chlorine residual in the water. Ensure, however, that it doesn’t contain calcium. High calcium hardness can result in scale formation which isn’t desirable for pool surfaces.

Relying on a supreme-quality algaecide is advisable. Opt for one that’s effective, long-lasting, based on copper, and resistant to low temperatures. Engage a multi-purpose, stain-preventing agent, ensuring it removes both metal and mineral stains. Closing your pool with a winter pill or a closing powder offers extra protection. These substances disperse a loaded blend of enzymes and clarifiers that maintain pool health throughout the winter.

Application Techniques for Long-Term Protection

The second phase involves applying the chosen chemicals using correct techniques to achieve a long-term protection scheme. Backing up your choices with efficient application methods boosts your pool’s resistance to winter’s harsh effects.

Administer the shock treatment the night prior to pool closure. It is crucial to let the pump run overnight after shocking, permitting the pool chemistry to attain equilibrium.

For algaecides and other chemicals, the application differs; mix the chemical in a bucket of pool water first then scatter it around the pool. Through improved dispersion, you’re enabling these chemicals to effectively combat localized issues.

Incorporate the winter pill or closure powder into the skimmer basket, permitting slow dispersion over the winter.

Maintaining a systematic approach to winterization helps increase your pool’s lifespan and readiness for the subsequent opening season. It bolsters both the efficiency of your efforts and the overall quality of your pool experience.

Covering Your Pool

Selecting the Correct Pool Cover

Your choice of pool cover significantly impacts the life of your swimming pool. For your pool’s winterization, use a safety or solid cover, both designed to withstand harsh winter conditions and prevent any contaminants from invading your pool.

  1. Safety covers, popular for in-ground pool owners, are made of a sturdy, porous material to allow snow and rainwater to seep through. Mesh safety covers are light, making them easy to install and remove.
  2. Solid covers, on the other hand, block sunlight from reaching the pool water, preventing algae growth. However, a solid covered pool must be opened before the weather turns warm; otherwise, it could host an algae bloom.

Securing the Cover for Winter

A cover won’t protect your pool if it’s not secured properly. Inflatable air pillows or ice compensators placed in the center of the pool ensure an even distribution of pressure from accumulating snow and ice. After inflating the pillow and placing it in position, use a cable or winch that runs through the cover’s grommets to secure it.

Water bags, pool cover weights, or winter cover clips can also provide additional security against winter winds. Remember, it’s essential that you frequently check your pool cover throughout the winter months for any potential problems like sagging, ripping, or pooling water. Doing this ensures your pool remains clean and protected from any winter weather that comes its way.


So, you’ve learned the ropes of closing your pool. It’s not just about slapping on a cover and calling it a day. You’ve seen how important it is to balance your water chemistry, clean out any debris, and adjust the water levels. You’ve understood the significance of winterizing your pool equipment and the role of algaecides and other chemicals. You’ve also discovered the value of choosing the right cover and securing it properly to protect your pool from the harsh winter elements. And don’t forget the ongoing maintenance – regularly checking your cover for any issues. Now, armed with this knowledge, you’re ready to close your pool like a pro. So go ahead, give it a shot. You’ve got this!

To successfully winterize and close your pool, start by thoroughly cleaning it, removing all leaves, debris, and algae. Ensuring balanced water chemistry before closing is also vital; adjust pH levels to between 7.2 and 7.8 and alkalinity to 80-120 ppm, as recommended by This Old House. Next, lower the water level to prevent freezing damage, remove all pool accessories, drain the pump and filter, and blow out the water from the plumbing lines to avoid cracks caused by freezing water. For a detailed step-by-step guide, ARM & HAMMER™ provides comprehensive instructions on these processes.

Frequently Asked Questions

1. Why is it important to close my pool properly for the season?

Properly closing your pool is essential to maintain the balance of your water chemistry and protect your pool equipment. This process involves adjusting pH levels, alkalinity, chlorine concentration, and calcium hardness, ensuring a clean and balanced pool when reopening.

2. What is involved in testing the water balance and chemistry of my pool?

Testing your pool’s water involves checking the pH levels, alkalinity, calcium hardness, and chlorine concentration. This helps you maintain the proper water balance and prevent corrosion or scaling on pool surfaces.

3. Why should I winterize my pool equipment?

Winterizing your pool equipment, including filters, pumps, and heaters, is crucial to prevent damage due to freezing temperatures. It also helps prolong the lifespan of your equipment.

4. How do I choose the right pool cover for winterization?

The right pool cover for winterization depends on your pool and personal preferences. Safety covers and solid covers are popular choices, each offering certain advantages. Consult a pool professional to make an informed decision.

5. How do I properly secure a pool cover?

To secure a pool cover, you can use inflatable air pillows, ice compensators, cables, water bags, or clips. These help protect your pool from winter elements and prevent damage to your cover.

6. How often should I check my pool cover during the winter season?

It’s advisable to regularly check your pool cover throughout the winter. Look for issues like sagging or ripping, as this could compromise the cleanliness and protection of your pool. Regular checks ensure early detection and resolution of any issues.