Pool covers are one of the most effective accessories for maintaining water quality, conserving energy, and ensuring safety around your swimming pool. However, knowing exactly when to put your pool cover on isn’t always straightforward—it depends on a variety of factors including climate, pool usage, and the type of cover you have. In this comprehensive guide, we’ll explore everything you need to know about pool cover timing, helping you make informed decisions that extend the life of your pool and save you money.
Understanding the Importance of Using a Pool Cover
Before diving into the specifics of when to use a pool cover, it’s crucial to understand why it’s necessary. A quality pool cover serves multiple purposes:
- Reduces water evaporation
- Minimizes chemical consumption
- Prevents debris from entering the pool
- Enhances energy efficiency by retaining heat
- Improves pool safety, especially with safety covers
According to the U.S. Department of Energy, pool covers can reduce evaporation by 30 to 50 percent, which not only conserves water but also reduces the energy cost associated with heating the pool. Knowing when to cover your pool can maximize these benefits.
Types of Pool Covers and Their Ideal Usage
Not all pool covers are created equal. Understanding the type of cover you have is essential for determining when and how to use it effectively. The main types of pool covers include:
Solar Covers (Solar Blankets)
Solar covers are made from a UV-stabilized polyethylene material that traps heat from the sun. They help warm the water while simultaneously reducing evaporation and chemical consumption.
Winter Covers
Used primarily during the off-season, winter covers are durable, solid covers that fully seal the pool to prevent debris, rainwater, and sunlight from affecting the water quality. They are often installed using water bags and straps to secure the edges.
Safety Covers
Safety covers are reinforced with webbing and are capable of supporting the weight of children and pets. These covers are secured with anchors bolted around the pool’s perimeter and are ideal for pools in residential areas.
Automatic Pool Covers and Solid Covers
These are mechanical or manual systems that offer convenience and high efficiency. They are typically used daily, especially in commercial settings or homes with high safety concerns.
Best Times to Put Your Pool Cover On
Now that we’ve reviewed the different types of covers, let’s explore the optimal times to deploy them based on pool usage, environment, and operational goals.
Daily Use Covers
Safety and automatic pool covers are designed for daily or frequent use. If you use your pool occasionally or want to prevent accidents, particularly with children or pets, it’s best to deploy the cover whenever the pool is not in use. In high-traffic environments—like resorts or backyard pools—these covers should be closed every evening or after swimming sessions.
For saltwater pools, keeping the cover on when idle is especially important. This reduces evaporation, preventing salt buildup and limiting the need for frequent filtering and balancing.
Evenings and Overnight
It’s especially effective to put on a solar cover during the evenings and overnight. This ensures that the heat collected during the day is not lost through evaporation. If your pool is solar-heated, a cover is essential for maintaining a consistent water temperature.
For chlorine-based pools, covering the pool overnight helps reduce sunlight-induced chlorine evaporation. Chlorine breaks down faster when exposed to UV light, so covering the pool during off-hours can prevent excessive chemical use.
Seasonal Pool Closure
Winter covers are typically used during the colder months when the pool is not in active use. The timing for applying a winter cover usually depends on your climate zone:
| Climate Zone | Recommended Time to Cover |
|---|---|
| Cold Climate (Northern U.S., Canada) | Late September to Mid-October |
| Moderate Climate (Southern U.S., Europe) | October to November |
| Warm Climate (Southwest U.S.) | November to December |
Before installing a winter cover, it’s essential to balance the pool water, clean the pool thoroughly, and apply winterizing chemicals. Failure to prepare the pool correctly can result in stains, algae growth, or cloudy water when reopening.
During Pool Maintenance or Chemical Treatment
After shocking your pool or applying special treatments like algaecide or clarifier, it’s advisable to cover your pool to allow the chemicals to work more effectively. Covering the pool during this time:
- Prevents dilution from rainwater
- Reduces UV degradation of chlorine-based chemicals
- Keeps debris out, allowing the treatment to target contaminants alone
This is particularly useful for solar and safety covers, although automatic systems are ideal when repeated access is required.
Weather-Based Coverage Decisions
The conditions in your area play a critical role in the timing and frequency of pool cover use.
High Winds and Dusty Conditions
In dry or windy climates, uncovered pools accumulate dust, pollen, and airborne debris continuously. Pools in desert areas, like Arizona and Nevada, should be covered at night and during strong wind events. A pool cover in these conditions can cut cleaning time by 50% or more.
Heavy Rainfall or Stormy Weather
While some rainwater can benefit chlorine pools by diluting chemicals slightly, heavy rainstorms can imbalance chemical levels and bring organic matter into the pool. It’s wise to cover your pool when heavy storms are expected, especially if you’re not around to monitor the water afterward.
Freezing Temperatures
In regions that experience regular sub-zero temperatures, the pool cover becomes part of winterizing the system. Applying a winter cover before freezing temperatures ensure that ice formation is minimized and that the pool walls aren’t damaged by ice expansion.
Usage Patterns and Pool Cover Timing
How often and when people swim influences the timing and type of pool cover strategy needed.
Regular Use Pools
For families that swim daily or hosts that use the pool often, automatic or safety covers should be used every time the pool is not in active use—typically after sundown or during long non-use intervals. These covers maintain water temperature, reduce maintenance costs, and provide added safety when not swimming.
For backyard pools in hot regions, solar covers can be used during non-swimming hours to maintain warmer water and reduce chemical usage.
Occasional Use Pools
If you only use your pool on weekends or select days, it’s best to keep it covered throughout the week. This reduces the frequency of cleaning, chemical adjustments, and heater usage. A solar cover can still help retain heat, making the pool more comfortable on weekends without needing extra heating time.
Commercial and Public Pools
Public and resort pools benefit greatly from automatic or mechanical covers. The ability to cover and uncovers quickly maximizes operational efficiency. These types of covers should be used whenever the pool is closed to swimmers—overnight, between swim times, and during closure periods.
Implementing best practices for cover use in commercial pools also helps comply with health regulations and safety standards.
Common Mistakes in Pool Cover Timing
Even seasoned pool owners sometimes make errors in when (and how) they use pool covers. Knowing what to avoid can help you make smarter decisions.
Leaving Covers On for Too Long
While pool covers are incredibly beneficial, leaving them completely closed for extended periods without proper aeration can promote algae growth. This is especially true if the pool water is improperly balanced before covering. Try to remove the cover periodically—especially solar or lightweight covers—to allow aeration and manual skimming.
Using Covers in High Winds Without Proper Securing
Certain types of pool covers can become airborne if not properly anchored during windy conditions. This not only diminishes their protective role but also poses a danger as large fabric sheets can fly around your property. Always ensure your cover is properly fastened, especially in storm-prone areas.
Forgetting to Adjust Chemical Treatments with Covers
Some homeowners continue to use the same amount of chlorine even when using a pool cover regularly. This can lead to over-chlorination. Your chemical use should decrease by up to 60% when using solar or quality winter covers daily. Regular water tests will ensure you’re maintaining the right balances and not wasting chemicals.
Best Practices for Pool Cover Maintenance
Knowing when to apply your pool cover is only part of the equation—proper care and maintenance of the cover itself ensure it lasts for years and performs optimally.
Routine Inspections
Check your cover regularly for tears, seams, and wear—especially at pressure points. Solar covers can become brittle over time due to repeated exposure to chemicals and UV light.
Cleaning the Cover
Before putting your pool cover away each season, wash it with a mild detergent and freshwater to remove accumulated chemicals, oils, and debris. This prevents UV degradation and prolongs cover life by years.
For safety and automatic covers, it’s crucial to have them professionally inspected and serviced once a year to ensure mechanical or motor functions are optimal.
Proper Storage
During off-seasons, pool covers should be stored in a cool, dry place away from direct sunlight. Using a designated cover reel for solar blankets protects them and makes deployment easier the next time. Winter covers should be dried and stored in a sealed container with desiccant packs to prevent mold growth.
When Is It Safe to Leave the Pool Uncovered?
While covering your pool has many benefits, there are situations when leaving it uncovered is acceptable or even necessary. These include:
Daily Pool Use and Swimmer Access
If you swim frequently or have open swim hours in a community setting, leaving the pool uncovered during the day is acceptable. Just ensure to cover it during non-use hours.
Aeration and Algae Prevention
If your pool is showing early signs of stagnant water or low pH levels, brief periods with the pool open and circulating the water can be beneficial before re-covering.
Sunlight Exposure and UV Pool Sanitation Systems
Some advanced pool systems use UV-C filters to sanitize water. Leaving the pool uncovered during sunny hours complements these systems by allowing natural UV breakdown of contaminants.
How to Choose the Right Pool Cover for Your Needs
Ultimately, the timing of when to put your pool cover on also depends on the type of cover you have. Here’s a quick breakdown to help you choose the ideal option:
| Pool Cover Type | Best For | Recommended Use Times |
|---|---|---|
| Solar Cover | Heat retention, chemical savings | Overnight, occasional use |
| Winter Cover | Seasonal pool closure | Cold-season storage |
| Safety Cover | Child and pet safety | Whenever pool is closed |
| Automatic Cover | Convenience and efficiency | Daily, frequent use |
Choosing the right type ensures that your usage habits align with the cover’s purpose and helps you decide when to deploy it at the right time.
Conclusion: Timing Is Everything with Pool Covers
Knowing when to put your pool cover on is essential for optimal pool health, cost savings, and safety. Whether you use your pool daily, seasonally, or occasionally, there’s a timing strategy that works best for your situation.
By considering your climate, pool usage, cover type, and maintenance goals, you can make informed decisions about when to cover your pool to maximize its lifespan, energy efficiency, and cleanliness. Combine this timing approach with regular maintenance to get the full benefits your pool cover can offer.
Implementing these best practices today can lead to better water quality, reduced chemical expenses, and a longer-lasting pool. Whether you’ve just installed your first pool cover or you’re refining your routine, timing it correctly will make all the difference.
When is the best time to put a pool cover on in the fall?
The best time to put a pool cover on in the fall is when the pool water temperature drops below 65°F (around 18°C) and swim season has clearly ended. This is typically after the first light frost in colder climates or when nighttime temperatures consistently fall below 50°F (10°C). Covering your pool at this stage helps prevent leaves, dirt, and debris from accumulating in the water over the winter months, reducing maintenance efforts in the spring.
Additionally, it’s important to make sure your pool is clean, balanced, and winterized properly before applying the cover. Algae or imbalance in the water can lead to serious issues under the cover, including staining and damage. Proper winterization includes adjusting the water chemistry, lowering the water level, adding winterizing chemicals, and installing a sturdy cover that’s securely fastened.
Can I put a pool cover on during the swimming season?
Yes, you can put a pool cover on during the swimming season, and doing so can offer several benefits. Safety and solar covers can be used when the pool is not in use to retain heat, reduce evaporation, and keep debris out. Pool covers during the season also prevent accidents and keep the pool cleaner, which reduces the workload on your filtration system and helps maintain chemical balance.
However, it’s important to choose the right type of cover and manage usage carefully. Solar covers should be removed before swimming to avoid overheating the water and to prevent damage from swimmers pulling on the cover. Safety covers can remain in place but must be properly installed to allow for safe access and egress. Using a cover properly during the season can save money and time on maintenance while improving your pool experience.
What type of pool cover should I use and when?
There are several types of pool covers, and choosing the right one depends on the time of year and your needs. Solar covers are best used during the swimming season to retain heat, reduce evaporation, and keep the pool clean. They are lightweight and easy to manage, and are typically removed before swimming and replaced afterward.
Safety covers, on the other hand, are used during off-season months to protect the pool from debris, pests, and unauthorized access. They are sturdy, durable, and often attached permanently with anchors around the pool deck. Winter covers are thicker and designed to withstand harsh weather and UV exposure. Selecting the right cover and timing its use properly ensures maximum protection and efficiency throughout the year.
Should I cover my pool at night during the summer?
Yes, covering your pool at night during the summer can be beneficial, especially if you’re using a solar cover. A solar cover helps retain the heat absorbed during the day, keeping the water warm without running the heater. It also prevents evaporation, which conserves water and reduces the need to replenish chemical levels lost through evaporation.
Nighttime cover usage is also useful when the pool is not in use for extended periods. It keeps debris out and reduces heat loss, leading to a cleaner and more energy-efficient pool setup. However, ensure the cover is properly removed before swimming to avoid safety hazards and to prevent unnecessary wear and tear caused by swimmers pulling on the cover.
How long can I leave my pool cover on?
While a pool cover can be left on for extended periods, especially during the off-season, it’s important to check the water beneath periodically. For winter covers, removing the cover at least once a month in milder climates can help you inspect the pool water and ensure chemical levels remain balanced. This also allows you to pump off water that collects on the top of the cover to prevent sagging or tearing.
During the swimming season, it’s best to avoid leaving a cover on for more than a couple of days at a time. Prolonged use can restrict gas exchange, leading to water chemistry issues, algae growth, and cloudy water. If using a solar cover frequently, remove it during pool use and allow the water to circulate fully to maintain clarity and balance.
What are the consequences of putting my pool cover on too early?
Putting your pool cover on too early can lead to several issues, especially if the water is still warm. Algae can begin to grow if the water isn’t properly balanced before covering, and the lack of circulation can exacerbate the problem. Warm covered water also creates an ideal environment for bacteria and organic debris to break down, potentially staining your pool surface or creating unpleasant odors.
Another downside is the possible condensation buildup beneath the cover, which can reduce its lifespan and effectiveness. Covering the pool too early may also trap heat, leading to increased evaporation when the cover is removed later. Timely winterization according to local climate conditions and water temperature is essential for avoiding these problems and ensuring a smoothly maintained pool when it’s time to reopen.
How do I properly secure a pool cover to prevent damage from weather?
Properly securing a pool cover is crucial to prevent it from blowing off or collecting standing water, which can damage both the cover and the pool. For safety and winter covers, use water bags, cover reels, or solid anchoring systems that are attached around the pool deck. Make sure the cover is tight and free of wrinkles that could collect debris or rainwater that might tear the material.
In windy areas, additional anchors and edge straps can help reinforce the cover’s attachment. Solar covers can be managed with a reel system to keep them taut and easy to remove. Regular inspections to pump off water and make sure the cover remains intact during storms are also important. Taking these precautions can significantly extend the life of your cover and protect your pool throughout the off-season.