Can I leave a solar cover on or off in winter?

Can I leave a solar cover on or off in winter?

Solar Pool cover

I get it, a swimming pool is one of the most precious possessions in our homes. 

Protecting it from dangers is a priority for anyone looking to preserve their truest source of our summer delights. 

One question asked often, is whether or not you need a solar cover on or off over the pool during the winter months. 

Table of Contents

What is a Solar pool cover?

A solar pool cover is basically a large plastic cover that comes in various sizes, thicknesses, and colors. This large plastic sheet lies on top of your swimming pool.

Types of Solar pool cover

Solar Blankets (also known as bubble wraps)

These covers don’t actually heat the pool up, instead they absorb heat from the sun and stabilizes the heat throughout your pool’s area. 

The sheet helps in reducing the process of evaporation and transmits heat to the pool. An added advantage of Solar blankets is that it helps in retaining chemicals in the pool and preventing loss of heat.

Solar rings

Solar rings are similar to solar blankets. They’re smaller rings that float on the pool and basically have the same functionality. 

Liquid solar covers

They’re ultra-thin molecule layer of alcohol that again helps in the prevention of evaporation and heat loss.

How does it work?

The Solar pool cover absorbs energy from the Sun and transmits heat to the water. You can save huge bucks when compared to pool heaters that run on electricity.

 I found an informative video on Youtube that explains how pool cover works.  

Check it out!

Can you leave Solar cover all winter?

In most cases, it is not advised to keep the solar cover ‘on’ during the winter. On the contrary, it fortifies the pool from debris, leaves, and the growth of algae. This applies only when you use your pool during winter.

If you’re not planning to use your pool during winter, it is recommended to remove the solar cover off the pool. 

Let me also brief you on the risk factor associated with leaving the Solar cover on. If you have chemicals in your pool, the concentration of Chlorine might go above 2.5 which leads to damaging the solar cover. Debris and other dirt particles that get trapped on the solar cover would weigh down, damaging the solar cover, therefore deteriorates its property.

But the benefits are that it prevents chemical and water evaporation from the pool, making it a lot easier and economical to maintain your pool.

 As a bonus, the solar panels will keep your pool insulated and warm in time for when you open it next summer. Furthermore, whilst there are alternatives to using a solar cover, they tend to be more labor-intensive and expensive. 


The next step is to purchase the best cover for your needs. Put simply, you have the option to choose between different colors and sizes. 

As a benchmark for size, ensure that the blanket is slightly larger than the pool’s area (in square meters).

What happens if you don't cover your pool in winter?

In case you leave your pool uncovered during winter, you will find leaves, debris, and also algae all over your pool. This might even affect the liner of your pool adding additional cost to get it repaired. 

It is recommended to drain your pool during winter when not in use. 

What is the best thickness for a solar pool cover?

The thickness of the Solar pool cover largely varies from 8mils to 16mils. The thicker the cover is, the better is it’s performance. 

Keep in mind that maintenance plays a key role when it comes to owning a swimming pool at your place.

Thicker pool covers can resist solar wear and tear and chemical burning when compared to thinner ones.

The higher the thickness of the pool cover, the greater is it’s property to retain heat. So go for 8-16mils if you’re planning to buy one for your pool.

What is the best color for solar pool covers?

When choosing the color, remember that the darker it is, the less heat the pool can absorb.

 The lighter and more transparent it is, the more sunlight it can absorb, from which the water can absorb more heat to remain warmer.


Blue solar covers can measure  4mil and 8mil(lasts about a year or two) whereas Clear/transparent solar covers can measure 12mil and 16mil(lasts about 5-10years).


On the other hand, darker and more opaque covers are better for the prevention of biological growth (like algae), despite their relative inefficiency in keeping the pool warm.

How to clean or maintain a Solar Pool Cover?

Prior to applying a solar cover, make sure to first brush off any dirt, then wash it with clean tap-water to finish the job. 

To extend their lifespan, (and save you money), keep them away from any heat above 100 degrees F. 

Also, bear in mind that exposure to water with higher chlorine levels than “three parts per million” can also damage the cover through corrosion.

Once you have the cover all cleaned and ready, apply it with the bubbles facing down and tuck the edges into the skimmers to keep it in place. 

Here are a few steps you could follow to maintain your cover from getting damaged when not in use


Store your cover in winter or when you’re not using them in an airtight or dry container. This will make sure your cover is in good shape for longer use.


Do not leave the Solar cover on direct sunlight when not in use. This will spoil your Solar cover resulting in an additional cost to your cleaning process.


Clean Solar pool cover

It is important to clean your Solar cover before you store them. Hose off your pool blanket in order to remove Chlorine, algae and other trapped particles on the surface. Give a soft brush on the surface by spraying cold water. Make sure you dry it properly before moving it to storage.

How to install a solar cover

Once you’re done cleaning your cover, it’s time to install it on the pool.

  • Place the solar blanket on the pool with the bubble side down
  • Make sure there are no air bubbles while you place the cover on top
  • In case you find the pool cover to be large, cut the extras on the side with a pair of scissors

Is it okay to run a pool with the solar cover on?

And, finally, never use or run a pool with a solar cover on. If an unlucky stroke of wind blows against the blanket, it could trap the swimmer, and also threaten to damage the cover if exposed to all the elements of the pool. 

How to 'winterize' your Solar cover?

Before we finish, what you can also do, is to “winterize the pool”

This adds another layer of protection to your pool regardless of whether you use a solar cover or not. 

To do that, firstly clean out the pool of all debris, reduce the water level by 1 to 6 inches, and then treat the water with bleach or additional chlorine. 

Then, remove any excess water from pipes, apply anti-freeze, and plug all inlets to prevent further intrusion of water. (If that sounds too cumbersome, then hire a professional to do that for you).

Impact of Chlorine

Chlorine that is used as a disinfectant in water, is highly corrosive in nature. When your pool is chemically sanitized, that implies that your water contains Chlorine in it.

Chlorine that is present in a liquid state in your pool, tends to evaporate or returns to its natural state, i.e gas, and tries to escape from the surface of the pool.

When a Solar cover acts on the surface of the pool, the gaseous state of Chlorine tries to escape and gets trapped as a result. The interaction of Chlorine-water might contribute to the degradation of the Solar cover, hence good care must be taken while using a Solar cover.

Final thoughts...

There, your pool should now survive (if not thrive) during the cold months of the winter. Maintain a regular watch over the pool cover to see if it is performing its duty well! 

Other than that, happy pool covering!

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