Solar pool covers heat the water and prevent evaporation, keeping the water warm and chemically balanced.Dimensions / Getty Images
This polyethylene translucent light-blue solar pool cover from In The Swim comes in both rectangular and round shapes, as well as various sizes. After five to seven days of consistent sunlight, the cover can increase the temperature of the water by 8 to 10 degrees Fahrenheit, according to the brand. Because of the light blue color, it can absorb and retain heat in the medium range and offers protection against chemical breakdown, says our experts.
If you have an oval-shaped pool, consider this option from Sun2Solar. If needed, it can be trimmed to fit your pool. Leaving this on your pool can help raise the temperature by up to 15 degrees Fahrenheit and will help to prevent water evaporation, according to the brand. The material is lightweight, making it easy to place over your pool. This cover has a 4.2-star average rating from over 1,250 reviews on Amazon.
If you live in a warm climate and have a round aboveground pool, this thinner, 8-mil solar pool cover is sufficient to increase your pool’s water temperature. In fact, according to Blue Wave, it can increase your pool’s temperature up to 15 degrees Fahrenheit, saving you on heating costs. Its opaque, light-blue color allows the maximum amount of sunlight to reach the water and is resistant to UV rays damage. The brand says it can also reduce water and chemical evaporation from your pool by up to 95%. It comes in 12-, 21- and 24-foot sizes and has a three-year manufacturer’s warranty and a 4.2-star average rating from over 3,270 reviews on Amazon.
This heavy-duty blue solar pool cover comes in six sizes and two thicknesses and offers options for aboveground and inground pools. It is made up of thousands of air bubbles to absorb UV rays and lock in the temperature. The brand says it can also reduce water evaporation by 95% while maintaining the pool’s chemical composition. This cover has a 4.5-star average rating from over 610 reviews on Amazon.
Made for aboveground pools, this round, blue solar pool cover comes in sizes that will fit pools that are 9.5-, 12-. 15-. 16- and 18-feet in diameter. The cover floats on the surface of your pool and reduces water evaporation by 95% and it is covered with tiny air bubbles that absorb the sun’s heat and transfer it to the pool water, according to the brand. This Intex aboveground cover has a 4.2-star average rating from over 33,110 reviews on Amazon.
This solar pool cover is available in sizes — from 12 feet by 20 feet up to 20 feet by 40 feet. This pool cover transfers the sun’s heat to the water when placed with the bubbles down. It also keeps leaves and other debris out of our pool. This cover has a 4.3-star average rating from nearly 400 reviews on Amazon and is 12 mils thick, making it ideal for moderate climates. This cover also folds down compactly, making it easy to store, according to the brand.
This solar cover has a patented quadrupel bubble design, which allows the sun to transfer heat to the water more easily, according to the brand. It is also extra thick to provide more durability. The sides are also edged with PVC to prevent them from fraying or tearing.
Choosing the best solar pool cover depends heavily on the size of your pool, your local climate, sun exposure and whether you want your cover to absorb heat or retain it, our experts told us. To figure out which type of solar cover will best meet your needs, Dobrica says you must first confirm these four factors before you can decide on the best size, color, material, UV resistance and thickness to best suit your needs.
The size of your pool. You need to cover the pool from edge to edge, says Gilda Dobrica, founder of ProSwim NYC and creator of the Teach-Your-Child-To-Swim e-course. So before you shop, measure the width and length of your pool from edge to edge exactly. If your pool cover is slightly larger than your pool, you can usually cut it to size without voiding the cover’s warranty. Large, high-quality solar pool covers close to 800 square feet may cost more than $200, whereas a smaller cover, closer to 100 square feet, will be about $100 or less.
Sun exposure. Pools that receive a lot of direct sun during the day benefit most from a solar cover because it will heat your pool quickly and efficiently. If your pool is shaded, the cover is much less effective. If your pool does sit under direct sun all day long, a UV protectant built right in will protect it from sun damage.
Local climate. Wind, air temperature and sun all affect the effectiveness of a solar pool cover and will greatly determine the color, thickness and material you should choose. For instance, if you live in a windy climate, you should opt for a thicker, more durable cover that is 16 mil and made of vinyl, which is more rigid; in a hot and sunny climate, an 8-mil cover made of polyethylene may be sufficient enough. Are you trying to retain your pool’s heat overnight, or do you want to attract more heat to make your pool warmer overall? Do you use your pool a lot? All of these questions will directly impact your choice of solar covers. For instance, a clear solar cover absorbs the most direct sunlight, leading to quicker chemical breakdown, so you must check levels regularly. Dark blue, black and opaque solar pool covers keep your chemical consumption in check and are better for retaining heat, which makes them a good choice if you aim to keep your pool warm overnight. If you use your pool often, you may want to consider a cover made of polyethylene, which is more flexible and easier to take on and off.
Thickness. Thicker pool covers (14 mils to 16 mils) offer better insulation in colder, windier climates, says Dobrica. Thin pool covers — around 8 mils to 10 mils — can save you about $100, broadly speaking, and may be sufficient in warmer climates. Solar pool covers with a thickness between 10 mils and 12 mils fall in the medium range.
Material. The most common types of solar pool covers are vinyl, polyethylene and polypropylene. All are non-permeable and designed to absorb sunlight and avoid evaporation, but the benefits vary. Vinyl covers are the most durable, which means they are less inclined to tear. Polyethylene covers are lighter in weight and less rigid than vinyl, but they aren’t as durable. Polypropylene covers maintain heat very well but are thick, making them more difficult to maneuver.
Color.“A UV-protected, translucent blue color offers a better balance between heat retention and pool chemical protection,” Dobrica says, adding that a clear cover will warm the pool water the most. Still, it will also allow more UV rays, making chlorine less effective as a disinfectant. A chemically imbalanced pool without enough chlorine could lead to algae blooms. Solar pool covers come in many colors: clear, light blue, silver, dark blue or black. Choosing the right color is important because it determines how effectively the cover transfers heat and blocks UV rays.
UV resistance. If your pool is in direct sunlight, you will want to consider a solar cover’s level of UV resistance to ensure it can withstand long-term exposure to the sun. Our experts say covers that are thinner than 10 mils and translucent have less resistance.
Frequently asked questions
Solar pool covers have two sides: a flat side and a side with air bubbles, which you place facedown in the pool water. When sunlight hits the flat side of the blanket, it warms the air in the bubbles, which heats the water. In addition to heating the pool, Dobrica says, the air bubbles on solar pool covers also serve as insulation, preventing more heat from escaping the pool water as the weather cools later in the summer season.
Solar pool covers can help reduce evaporation from your pool, its heat loss and keep important chemicals in the water. Since the atmosphere is almost infinitesimally cold, heat from ground-level soil and water will radiate to the atmosphere, especially if it’s colder, later in the day and when skies are clear, says Stephen Carr, a professor emeritus of materials science and engineering at Northwestern University. “A pool could easily lose 5 degrees Fahrenheit worth of temperature just due to radiation at night,” he says. Chlorine in pools is “volatile” and will be released into the air from the water, Carr says, explaining that this is why your eyes may hurt when swimming in an indoor pool — what you’re feeling is the chlorine gas that’s evaporated from the pool. Reducing the evaporation can keep those necessary chemicals in the water, saving you money on heating and chlorine costs.
At NBC Select, we work with experts with specialized knowledge and authority based on relevant training and/or experience. We also ensure all expert advice and recommendations are made independently and without undisclosed financial conflicts of interest.
Gilda Dobrica is the founder of ProSwim NYC and creator of the Teach-Your-Child-To-Swim e-course.
Stephen Carr is professor emeritus of materials science and engineering at Northwestern University.
Barbara Booth has published several roundups for NBC Select, including Best vacuums under $100, Best ellipticals and Best exercise bikes. For this piece, Barbara interviewed two experts and researched dozens of solar pool covers, choosing the most highly rated options that aligned with expert guidance.
