Make and Model Don't go for the make and models custom covers-the ones that claim that they fit on ANY hot tub.
Unfortunately, they probably don't and they probably won't protect your hot tub in the way that it needs to be protected.
You need to be aware, as mentioned above, of all of those things, so that you can choose a hot tub cover manufacturer that carries the right spa cover for you! Keep in mind that spas come in all shapes and sizes-there's no way that there could be an actual "universal" spa cover.
Year You'll also need the right year.
Sometimes a spa design will stay the same or very similar for a few years...
but more often, it won't.
So, try to keep the paperwork for your hot tub on hand so that you don't lose this information.
It might not seem like a big deal to toss it at first-you'll remember...
right? However, after a few years, this type of information turns rusty...
And, when it comes to covers, you really don't want to play a guessing game.
It could mean damaging your hot tub or ending up with a nasty pet algae swamp.
Size You want a relatively thick hot tub cover.
This will mean that you need about two inches in thickness and nearly five inches from around the outer edge of overlapping.
This will help to make the cover...
not water tight, but it won't allow anything little to slip through the cracks and if something falls on top of your spa, it won't split the cover in any way, shape, or form.
Plus, it makes things way easier on you, since you're less likely to end up damaging your spa cover.
Underside Look for spa covers that have non porous undersides-and then research them.
Make sure that the spa manufacturers aren't just CLAIMING that they have a non porous underside...
and make sure! You won't regret it later, that's for sure! There are plenty of different materials that work for the undersides of spa covers, but you need to make sure that you have the right one for your type of hot tub as well.
Otherwise, the cover will sag, become heavy, end up mildewed and moldy and gross, and you'll be out a bit of money for your hot tub cover.
Needless to say, it's fairly simple to pick out great spa covers...
you just need to know what it is that you're looking for.