10 Mistakes to Avoid When Closing Your Pool

Posted on: October 29th, 2025 by webolutions

Key Takeaways:
Proper pool maintenance during closing season prevents costly repairs and ensures an easier opening in spring. Avoid common mistakes like neglecting water balance, skipping equipment care or covering the pool improperly. Professional pool service can help you protect your investment and extend the life of your pool.

As pool season comes to an end, many homeowners rush to close their pools without realizing that mistakes made now can lead to serious problems later. From algae growth and cracked plumbing to damaged filters and liners, improper pool closing can turn your spring opening into an expensive headache. Whether you manage your own pool or rely on a professional pool service, taking the time to close it properly is essential for protecting your investment and ensuring a smooth start to next season.

Below are the most common mistakes homeowners make when closing their pool and how to avoid them. We also encourage you to review our pool winterization checklist to make sure you understand all the important steps involved in the process.

Not Balancing the Water Before Closing

One of the most critical yet overlooked steps in pool maintenance is testing and balancing the water chemistry before shutting down the system. If your pool water is unbalanced – too acidic, too alkaline or too full of contaminants – it can corrode equipment, stain surfaces or promote algae growth during the off-season.

What to do:

• Test pH, alkalinity and calcium hardness a few days before closing
• Adjust pH to between 7.4 and 7.6 and total alkalinity to between 80–120 ppm
• Shock the pool with chlorine or a non-chlorine oxidizer to kill bacteria and prevent algae growth
• Add a long-lasting winter algaecide to keep the water clear through the colder months

Skipping the Final Cleaning

Leaving dirt, leaves or debris in the pool before covering it can cause staining, discoloration and algae blooms. Many homeowners think the cover will protect the pool enough, but whatever’s left behind in the water can decay and disrupt the chemical balance. A clean pool at closing means far less cleaning and chemical use at opening.

What to do:

• Thoroughly vacuum the pool, and brush the walls and floor
• Empty all skimmer and pump baskets
• Use a leaf net or surface skimmer to remove any floating debris before applying your winter cover

Failing to Lower the Water Level Properly

Improper water levels are a common mistake that can cause damage to your pool cover and plumbing. If the level is too high, the water can freeze into the skimmers. If it’s too low, the cover can sag or tear.

What to do:

• For most inground pools, lower the water level to about 4–6 inches below the skimmer
• For above-ground pools with floating covers, follow the manufacturer’s recommendations – many suggest leaving the water level near the top
• Avoid draining the pool completely, which can cause structural damage or liner shrinkage

Neglecting Pool Equipment

Filters, pumps, heaters and plumbing lines are vulnerable to freeze damage if not properly winterized. One of the most expensive mistakes homeowners make is forgetting to drain and protect these components.

What to do:

• Drain all water from the pump, filter, heater and chlorinator
• Blow out all plumbing lines with an air compressor and plug them securely
• Store removable equipment like ladders, skimmer baskets and automatic cleaners in a dry, protected place
• For added protection, use pool-grade antifreeze in the lines (never automotive antifreeze)

Having a professional pool service perform this step ensures everything is fully protected and sealed.

Using the Wrong Pool Cover

A good pool cover is your first line of defense against debris and contamination. Using a cheap or poorly fitted cover can allow dirt, leaves and even pests to enter the pool throughout winter.

What to do:

• Invest in a high-quality, tightly fitted safety or solid winter cover designed for your pool’s dimensions
• Ensure the cover is securely anchored and tensioned to prevent sagging
• Periodically check the cover during the off-season to remove standing water or debris buildup

Forgetting to Winterize Accessories and Features

Many homeowners forget to winterize features such as waterfalls, fountains or attached spas. If these aren’t properly drained and protected, they can crack or leak due to freezing temperatures.

What to do:

• Drain all water from these features and blow out lines
• Store removable parts indoors
• Cover exposed plumbing or equipment to prevent weather damage

Even small oversights, such as leaving water in a return jet line, can lead to big repair bills in the spring.

Neglecting to Remove Pool Accessories

Leaving ladders, floats, toys or cleaners in the pool is an easy mistake that can cause staining, liner damage or corrosion.

What to do:

• Remove all accessories, clean them, and store them in a dry place
• If your pool has metal rails or diving boards, clean and dry them before storage to prevent rust and corrosion

Closing the Pool Too Late

Waiting too long to close your pool can cause algae growth and chemical imbalance, especially if temperatures stay warm for a while. On the other hand, closing too early can lead to algae blooms because the water is still warm.

What to do:

• The ideal time to close your pool is when the water temperature consistently drops below 60°F (15°C)
• At this temperature, algae and bacteria stop growing, and chemicals last longer

Closing at the right time ensures your pool remains clean and stable throughout winter.

Ignoring the Importance of a Professional Inspection

Even diligent pool owners can overlook small leaks or equipment issues before closing. A pre-winter inspection from a professional pool service helps catch these problems early, before freezing temperatures make them worse.

What to do:

• Schedule a pool inspection before closing
• Have a technician check for leaks, cracks and signs of wear in your equipment and plumbing
• Ask for recommendations on off-season maintenance and best practices specific to your pool system

Failing to Document and Plan Ahead

Another overlooked aspect of pool maintenance is tracking what was done at closing. Without notes, it’s easy to forget chemical levels, cover conditions or equipment maintenance come spring.

What to do:

• Take photos and make notes of your water test results, chemical additions and equipment status
• Keep these records in a binder or digital log for reference next season

A little organization can make your spring reopening faster, safer and less stressful.

Why Professional Pool Service Matters

Closing your pool properly isn’t just about draining water or putting on a cover, it’s about protecting your investment. A professional pool maintenance company has the tools, experience and expertise to:

• Accurately balance your water chemistry
• Properly winterize plumbing and equipment
• Ensure your pool cover is secure and fitted
• Catch hidden issues before they become expensive problems

Partnering with a trusted pool service gives you peace of mind that your pool will be clean, safe and ready for the first warm day of spring.

Allen Pool Service Can Ensure Pool Closing is Completed Properly

With so many critical tasks to perform as part of the fall pool closing routine, it’s easy to get overwhelmed and miss a step. Unfortunately, this can result in serious issues that require expensive pool repairs when you reopen your pool next spring. If you’d prefer to leave the process to the experts, Allen Pool Service will make sure every aspect of the closing routine is handled properly.

Allen Pool has been the leading pool service company in Atlanta since 1972. We provide comprehensive pool maintenance and repair services that will help keep your pool running properly for years to come. Our team takes pride in providing thorough work that ensures the job is done right the first time. When you work with us for your pool closing services, you’ll enjoy a hassle-free experience and have peace of mind that the process is handled correctly.

Contact us today to schedule an appointment. Allen Pool Service serves customers in Atlanta and the surrounding areas.