Just thought I'd share that I have this stuff a try. I was losing about 9-10 degrees over night and after putting in CoverFree that instantly dropped to about a 5 degree loss, with the same overnight conditions. So, from my limited exposure here (using it for about a week now), I'd say it does what it says - reduces heat loss from evaporation.

No, it's not a real solar cover - but it helps!