Did anyone study osmosis when they went to hot tub cover school?
If you feel comfy with a dealer, buy the spa he/ she's selling.
Yeah, the definition of osmosis is burned into my brain forever. Not trying to be a smart ass, but are you saying that all covers eventually become semipermiable membranes? Or that they all start out that way? Either way, obviously the message is to buy a tub for the tub, not for the cover.....