Frequent Questions
Swimming Pool Blankets

Absolutely. Most of your pool’s heat loss occurs through evaporation at the surface. A pool blanket blocks this evaporation, which keeps your pool warmer than a similarly situated pool without a blanket. A pool blanket supercharges the performance of a solar pool heater, and it can reduce the cost of running a gas heater or electric heat pump by more than half.

Most people use pool blankets during the coldest months of the year when a pool’s heat loss is the greatest. Pool blankets can greatly increase the efficiency of solar pool heating systems during the winter months, when pool surface heat loss is the greatest and the sun’s energy is the least intense. Without a pool blanket in place during the colder months, heat loss at the pool surface is more than a solar pool heater can offset.

Yes, pool blankets can be difficult to handle, especially for freeform swimming pools. You may want to keep this in mind if you are building a pool. One product that can make the job more pleasant is a pool blanket reel.

You might also experiment with a patented product called a “liquid pool blanket.” This is a liquid solution that is added to your pool water. The solution forms a thin layer across the pool’s surface that blocks evaporation and heat loss. This solution is completely invisible and non-toxic; in fact, the active ingredient is used in cosmetics and toothpastes. While a liquid pool blanket isn’t as effective as a conventional plastic pool blanket, it is much easier to use and does offer significant savings.

If you are using a conventional pool blanket without a reel, here’s what we recommend:

Avoid an “all or nothing” mentality. start by using the pool blanket at least during the two to three days when a severe cold front passes through, and during the winter months when trying to heat a pool without a pool blanket is like trying to cool your house with all the doors and windows open.

Finally, practice folding and storing your pool blanket with two people. You are more likely to use your pool blanket if you become comfortable handling it.

The most popular pool blankets are similar to blue plastic air bubble packing material. To increase durability, the pool blanket’s plastic contains UV inhibitors and is two to three times thicker than the plastic used in air bubble packing material.

Yes, but the term “solar” pool blanket is a misnomer. A pool blanket keeps heat in your swimming pool by stopping evaporation at the pool’s surface. Evaporation is by far the greatest cause of heat loss from a swimming pool. If evaporative heat loss is reduced, an unheated pool will stay warmer longer and less energy will be required to keep a heated pool at a given temperature.

On the other hand, a pool blanket does not help the pool surface absorb more solar enegy. In fact, a blanket actually blocks and reflects a very small amount of the solar energy that would normally be absorbed by the pool surface. But this effect is small and insignificant compared to the pool blanket’s dramatic ability to stop heat loss off the pool surface.

Yes. By blocking evaporation from a pool’s surface, a pool blanket also conserves water and reduces consumption of pool chemicals by 30 to 60 percent. The precise amount naturally depends upon how many hours the cover is in place.

Pool blanket reels offer convenience; however, many pool owners do not want the reel assembly sitting on their pool deck. For a typical residential pool, two people can very easily remove and fold a pool blanket in about two minutes.

To remove the blanket, each person stands at an opposite corner of the same end of the pool. Pull the corners of the blanket out of the pool, then step back and set the blanket down so that about three to four feet of the blanket is overlapping the pool deck. Next, each person should step forward along his or her side of the pool to a point roughly twice the length of the section of blanket resting on the pool deck (six to eight feet). From this point forward, simply repeat the process of pulling six to eight foot sections of the blanket back out of the pool and folding each section accordion-style on the pool deck.

With the blanket folded at one end of the pool, repositioning it on the pool surface takes less than one minute and is a simple matter of each person grabbing a corner of the blanket and walking forward to the far end of the pool.

Yes. A liquid pool blanket is a patented solution that, when spread across the surface of a pool, reduces evaporation from a calm pool surface by about 40 to 50 percent. Of course, a swimming pool is not always calm, and actual reported savings on heating costs range from 15 to 35 percent.¹

The liquid solution, marketed under the brand name Heatsavr®, is a mixture of alcohol and aluminum salt. Aluminum salt is a white flaky substance commonly used in cosmetics, soaps and toothpaste. It is safe, clear, tasteless, odorless and biodegradable. Alcohol is lighter than water, which allows the solution to form a thin film at the pool surface. A very useful property of the alcohol and aluminum salt mixture is that the molecules tend to rearrange themselves back into a thin sheet across the pool surface after pool activity, as the water calms. Also, the aluminum salt particles used in the Heatsavr® product are so tiny that they will not clog pool filters.

Liquid blankets are especially useful for larger residential and commercial pools and for unusually shaped pools, situations where handling a plastic blanket may be impractical. The Heatsavr® liquid solution is dispensed automatically, either from a metering pump dispenser or from a plastic container that floats in the pool. The most popular containers are shaped like tropical fish; the solution dispensed by one “fish” may cover up to 800 square feet of pool surface for two months.

While a liquid pool blanket is only about two thirds as effective as a plastic pool blanket, it may actually deliver better performance than a plastic blanket in real world situations if the inconvenience of removing and replacing the plastic blanket leads to inconsistent use.

First, as we explain above, a pool blanket does not heat your pool. A pool blanket allows your pool to stay at a higher temperature by stopping heat loss from the water surface, but it will not add heat to your pool. For that, you need a pool heater.

As for the white residue, that’s aluminum salt (see the previous question). If you add Heatsavr® solution to pool water that is colder than 70°F (21°C), the aluminum salt will solidify and collect at the water’s edge. This may also occur if you add too much liquid pool blanket solution in relation to your pool’s surface area. Don’t worry, though. It’s completely harmless, biodegradable, and will go away on its own.