When To Leave Your Pool Cover On: Should You Leave It On or Off During the Day?

Written by Michael Dean
November 30, 2023

pool cover with calendar and stopwatch

Owning a pool comes with a myriad of different responsibilities. Everything from cleaning your filter to looking after your pool cover is an essential part of pool maintenance. Although pool covers may not necessarily be on the top of a priority list for pool maintenance, looking after your pool cover can make a difference in prolonging the life of your pool. One of the most common questions I get asked regarding pool covers is when to use them. Should you leave it on or off during the day?

In this article, I will explain whether or not you should leave your pool cover on during the day.


Main Takeaways 

  • Solar pool covers should be left off during the day to allow for even heating of the water.
  • Pool covers should be taken off at least once a week to allow collected carbon dioxide to escape; too much carbon dioxide can make the water acidic.
  • Unless the pool is in use, pool covers should always be used at night.

Should Solar Pool Covers Be Left On During the Day?

I recommend removing your solar pool cover during the day as there are more advantages to doing this than if you were to leave the cover on. That said, if you decide to keep your solar cover on, it is not the end of the world. Just remember to take off the cover at least once a week to allow the collected carbon dioxide to escape and for your pool water to breathe. Here are some pros and cons of leaving your solar pool cover on or off during the day.

Pros 

There are a couple of reasons that would make leaving your solar pool cover on during the day desirable. 

  1. On windy days, you can leave your cover on to protect the pool water from the elements, such as leaves and debris. 
  2. Leaving your solar cover on during the day allows your pool to retain its temperature.
  3. Your solar cover also reduces the loss of water through evaporation. So it will save you the money and time spent refilling the pool.

Cons

There are also several reasons to keep your solar pool cover off during the day. 

  1. Leaving your solar pool cover on during hot days is not a good idea as it can negatively affect water temperature. Taking off the cover during a hot day may seem counterintuitive, but leaving the cover on will result in uneven water temperatures. I recommend allowing the sun to heat up the pool organically during the day.
  2. Another reason why pool covers should not be left on during the day is that the surface of the solar cover can end up getting damaged from the sunlight, shortening the lifespan of the pool cover and its efficiency.
  3. Solar covers also shouldn’t be left on in storms or harsh winter weather. The solar pool cover cannot handle the weight of debris and snow on the surface, so the cover will be at risk of tearing. I recommend using a solid pool cover for these conditions, as they are more durable.

Should I Leave My Solid Pool Cover On During the Day?

Unlike solar pool covers, solid pool covers are made of the sturdiest materials like PVC and are a lot thicker than other pool cover options on the market. Because of their thickness, it is recommended that solid pool covers are taken off during the day throughout the warmer seasons. By taking it off, you allow for the water to heat evenly throughout the pool, and you will avoid prolonged damage to the exterior surface of the pool cover. However, make sure when you do take it off, that you store your pool cover properly.

Here are some pros and cons of leaving a solid pool cover on or off during the day.

Pros

  1. Similar to solar pool covers, solid pool covers protect the pool from falling debris. Especially on windy days.
  2. Solid pool covers are usually designed to withstand harsh winter conditions and storms, so you can leave them on during the cooler months or when winterizing your pool. Leaving the pool cover on during the winter prevents the water from freezing and causing structural damage to the pool.

Cons

  1. Leaving the thick solid pool cover on all day every day under the hot summer sun can speed up the process of algae breeding if you don’t properly look after the chemical levels of the pool water underneath the cover.
  2. Although solid pool covers are more durable than solar pool covers, they can still be damaged by the sun’s UV rays. Prolonged exposure to the UV rays can result in damage to the pool cover.

If you’re concerned about debris entering the pool water, you can always install a lighter pool cover during the day, like a transparent solar cover or even a mesh pool cover.

When To Use a Pool Cover

Pool covers can technically be used all year round, but there are times when a pool cover is definitely needed.

When The Pool Is Not In Use 

This seems pretty obvious, but when you’re not using or planning on using the pool for some time, it is best to leave the cover on. If you’re going away on vacation, it is best to leave the cover on to protect the pool. When doing this, make sure that you secure your pool cover properly.

If you have a solid pool cover, make sure your chemicals are balanced so that algae doesn’t breed underneath while it is covered.

At Night

This is perhaps the best time to use your pool cover because the pool cover will keep the water temperature from cooling and prevent large amounts of water evaporation. Many pool owners even choose to put chemicals into the pool water at night as the cover prevents the loss of chemicals through evaporation. Keeping your pool cover on overnight will prevent debris from falling in your pool as well, leaving you with less cleaning to do in the morning.

Windy Weather

Windy and dry weather can be bad news for your pool. Using a pool cover during bad weather can prevent water evaporation and unwanted debris from entering the pool water.

In The Winter 

A cold, weather-resistant pool cover should be used during the winter when the pool is not in use. A thick, solid pool cover will protect your pool water from freezing and keep debris and snow off the pool water. Winter pool covers can withstand harsh conditions like cold, snow, and blistering winds.

Benefits of Taking a Pool Cover Off During the Day

A couple of benefits result from taking a pool cover off during the day.

Even Water Temperatures

Leaving your pool cover on during a sunny day may seem like it is helping to warm the water, but in reality, the water temperature is not likely consistent throughout. Solid pool covers, in particular, prevent sunlight from warming the pool water from the bottom to the surface of the pool. And since the sunlight heats the pool naturally and evenly, you can even save money by shutting off your pool heater and letting nature do its work in heating up your pool.

Prolong The Life of Your Cover

As mentioned already, using the pool cover every day can shorten the life of your pool cover as the material becomes vulnerable to tears and rips. Bad weather and standing rainwater can add stress to the seams of the cover, leaving the material loose and weakened. The chemicals you put in your pool may also cause your pool cover to slowly deteriorate. Taking off the pool cover during the day can give your cover a break.

Better Balance In pH Levels

Leaving pool covers on for long periods of time can result in too much carbon dioxide collected inside the pool cover, which can reduce the pH levels. Low pH levels cause the water to become acidic, and this can damage metal fixtures inside the pool pumps, filters, and even heaters.

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Bottom Line

Pool covers – both solar and solid – are a great way to keep debris off the water and to keep water from evaporating overnight. As they can save you time and money in the long run, you must take good care of them – even though they may not be complicated machinery. One way to take proper care of your pool cover is to know when to use it and when to take it off, along with cleaning your pool cover regularly. Now, with basic knowledge under your belt, you should see the life of your pool cover prolonged.

Do you have more questions? Let me know!

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