Despite all my jokes, here is one serious bit of advice:
Do not expect a solar cover to last more than 3 years. I've had all kinds from thin and cheap, to thick and expensive and they ALL die by the end of the 3rd season. The warranty ONLY covers seam failuress, not the bubbles. So i get the cheapest blue or clear one I can, and after 3 seasons, it doesn't hurt NEARLY as much to trash it as it does those that cost 2-3x as much, because they die before the 4th season as well.