'liquid solar blanket' for my pool, did I waste $10?

[Anachronism]

This is my first summer owning a pool. I just bought one of those plastic solar heating panels for my pool since I like warm water and want to be able to use my pool as soon as possible. I also learned that putting a ‘solar blanket’ on top of the pool will help keep it warm. (It looks like a giant sheet of bubble wrap) The solar blanket is a huge PITA to handle but I figured I would have to do it to keep my pool warm.

Then near the register I saw something called ‘liquid solar blanket’ :eek:. It is a weighted pouch in the shape of a fish filled with liquid, according to this site …

Evaporation accounts for up to 7/8 of heat loss from a swimming pool. TROPICAL FISHTM contains a liquid which automatically floats to the surface of the pool and acts as an evaporation inhibitor.

Our key ingredient is a non-toxic chemical called HEATSAVR; it’s been around for over 8 years and has a proven track record in commercial use. It is packaged to facilitate its application for your residential pool. HEATSAVR is filter friendly, does not affect the chemical balance (PH, chlorine, alkalinity) of the water, will not damage vinyl liners or any other pool surfaces, and is absolutely harmless to your skin.

Simply snip the fin where indicated and toss the fish in your pool. The TROPICAL FISHTM submerges to the bottom of the pool and as the pressure increases, the liquid escapes, rises, and forms an invisible layer on the surface of the water. It is 60% as effective as a conventional solar blanket but 100% less trouble. It works 24 hours a day, even while people are swimming. TROPICAL FISHTM will last for approximately 1 month. Then all you have to do is retrieve the fish and toss a new one in.

Does this sound like it could possibly work, or did I waste my $10?

[The_Man]

I’m not exactly sure how it would work. The idea of the blanket is to trap the evaporating water and condense it so it remains in the pool. A film of some sort on the water would seem to be significantly less effective, although I’m not sure. It is possible that the liquid reflects the light and does form a contiguous cover over the pool. Other than asking an expert (i.e. not me), your best chance is to test it yourself.

[Joey_P]

I’d be weary of this product. At the very least maybe you could e-mail them and ask them what the active ingredient is. (I’d imagine they’d have to tell you, what if your dog or kid ate one and you had to call poison control. Anyways, at the very least they need to learn how to market the item better, some of their statements are kind of counter productive

It is 60% as effective as a conventional solar blanket but 100% less trouble

Or

HEATSAVR theoretically could save half your heat bill if no one ever swam in the pool and if the circulation pump were turned off. This is not likely but HEATSAVR does achieve savings as high as 40%.

and some contradict each other like

each fish can cover 350-400 square feet of water surface and will last for about 30 days

and

Liquid Blanket biodegrades over a few days

They also claim to have been in use for the past 10 years at hotels, city pools and YMCA’s, perhaps you could contact a YMCA and ask them about it.

[scr4]

Once diluted with water, TROPICAL FISH™ is 100% non-toxic and safe.

So apparently it’s water-soluble. I don’t see how it can it get diluted by water and still “float to the surface.” I think some type of oil wold work as a “liquid blanket” but it would hardly be invisible.

[Q.E.D]

Evaporative cooling is the major cause of heat loss (up to about 70% not 87.5%, which is what 7/8 is) in pools and other bodies of water, from what I’ve read, however I’d have to wonder about the efficacy of a surface film of some unknown chemical to reduce this.

[Desmostylus]

scr4: It’s more likely to be a long-chain fatty alcohol, like hexadecanol or octadecanol, which does float, and has an OH on one end. The OH end stays in the water.

This type of thing is used to reduce evaporation from irrigation channels and dams.

I’ve got no idea what it does in pools.

[Desmostylus]

And the idea of using an alcohol rather that something like paraffin is to ensure that you get an even monomolecular layer across the surface.

[Q.E.D]

*Originally posted by Desmostylus *
**scr4: It’s more likely to be a long-chain fatty alcohol, like hexadecanol or octadecanol, which does float, and has an OH on one end. The OH end stays in the water.

This type of thing is used to reduce evaporation from irrigation channels and dams.

I’ve got no idea what it does in pools. **

I believe they use that same sort of thing to exterminate mosquito larvae. The larvae need to penetrate the water’s surface to breathe, but the surface tension of the lipids is too great for them to poke through, so they suffocate.

[Melraidin]

I don’t have any scientific evidence to add; this just to clarify.

Assuming it were a liquid that would float to the surface my first thought is that it is an oil. Simple, and I’d imagine effective, at decreasing evaporation.

Now while this may indeed work to decrease the rate of evaporation of water, what about collecting the solar energy? Many pool blankets that I’ve seen are made of simply a matte black bubble wrap, with the idea being that the black plastic will absorb heat better and avoid water evaporation.

Possibly I’m way off base on this, but I’d imagine that without having anything to ‘attract’ the sun’s rays you’ll not have a very effective solar heater.

I would really like to hear the opinions of people in the business though.

[Desmostylus]

More info can be found here, at the web-site of “flexible solutions”. I haven’t been able to work out what the active ingredient is, the safety information only details other ingredients like iso-propyl alcohol used as a solvent.

From a quick read through, it does sound legit. The inventor is an ex-professor of chemistry from the University of Victoria in Canada.