… no blanket?

What… no blanket?

A few years ago, during the winter months we would place out for our guest’s use a large floating pool blanket to cover the pool water at night. The blanket would float on the surface and reduce the temperature drop in the pool water over night. We no longer use these blankets, so you won’t find one at the villa any longer.

Why we stopped using it

The unfortunate truth is that even though it was in the guest’s best interest to use the pool blanket at night to keep the water as warm as possible, most guests would never use it. It is a hassle to put it on and take it off, requires two people to do or else it can’t be done quickly, and some guests felt “I’m paying for the pool to be heated, why should I have to take care of putting a pool blanket off and on?”

As a result, the blanket would be left in a crumpled heap on the pool deck, where it would collect rain water and dirt that would blow in. If later put on the pool, any dirt that had collected in the blanket would just then get dumped into the pool, or come off on the deck or in the pool when the blanket was removed for a swim, making for an unsightly mess.

A blanket on the pool also stops the ability of the skimmer to do its job, and keep the surface of the pool clean. Without the blanket, anything that falls into the pool and stays on or near the surface, relatively quickly ends up in the skimmer and its basket for later removal. With the blanket on, anything falling on the blanket stays on top of it, only to slide off into the pool when it is removed for a swim.

Would a roller help?

The cleanliness and convenience issues can be helped by having the pool blanket on a roller, but even with a roller in place, guests still rarely used the blanket.

And under the Florida sun, standard pool blankets quickly break down needing frequent replacement. When they do, they leave little bits of plastic in the pool – hard to see in the water, but noticeable and annoying when going for a swim (and take a toll on filters and equipment).

Certainly the pool is not nearly so attractive for our guests when they first arrive if it is hiding underneath a plastic blanket, as opposed to walking out on the deck and seeing a pool full of crystal clear water, and easily reaching into it and feeling its inviting warmth.

An Experiment

With all of this in mind, we decided to perform an experiment one year, and did not put out the pool blanket at all. It simply wasn’t available to guests, and nothing was said to them about it. Only one or two guests even noticed or mentioned the absence of a pool blanket, and when we reviewed our electrical bills for the year (the greatest indicator of whether a blanket is being used or not) we found absolutely no change.

This confirmed our suspicion that guests were almost always not using the blanket. We then made the decision to not put them out in the future.

The future Arrives

Another factor in our decision to stop using conventional pool blankets was the introduction and improvement over time of a new technology that would eliminate the need for them. Just as we have replaced the old with the new in other areas of our pool operations, such as with our high-tech variable speed, programmable pool pumps and our new energy efficient pool heaters, we have done the same with the pool blanket.

A new type of Liquid Blanket

We have replaced our old, conventional inconvenient and messy pool blankets with a new technology called a Liquid Blanket. A liquid pool blanket is a non-oily, non-greasy, invisible, odorless, inert and inorganic liquid polymer that you can’t see or notice in the water. What it does is float to the top of the pool water at night when the pool isn’t being used and the water is still, and it bonds together to create a microscopically thin layer over top of the water.

The greatest cause of heat loss in a pool is simple evaporation; those water molecules with the greatest thermal energy use it to escape to the atmosphere and take the heat with it. Old pool blankets don’t actually keep the water warm by insulating the pool nearly so much as they prevent evaporation.

Liquid polymer pool blankets accomplish the same thing. The incredibly thin layer of polymer floating on the water surface when it is still prevents the water from evaporating, thereby retaining most of the heat in the pool. The pool experiences greatly reduced heat loss overnight, without any of the hassles of conventional, old-style blankets.

Do liquid pool blankets prevent all heat loss overnight? Of course not, but then neither did old-style plastic blankets either. The pool will always lose some heat overnight, but this can be quickly replaced by our powerful and efficient pool heaters during the first part of the day.

Liquid pool blankets do need to be replenished, and their effectiveness will drop somewhat over time, until the next top up. If the pool seems unusually cool in the morning (significantly more than what you would expect from overnight temperatures) please do reach out to us and let us know. It may be time for a top up.

For further information, check out this post (coming soon) about winter pool heating and our thermal heat pumps.

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About the author:Rob Peters is the Site Administrator, Blogger and Chief-Touble-Maker on When not online, he is managing his terrific vacation rental properties in Florida, or admiring his three adult kids and loving his wife Donna.