Your original Hot Spring cover had 2# foam. Especially in northern Ohio, you'll want to stick with that. Our weather here in southern Ohio is milder but we even recommend to our customers down here to go with the 2# foam because it absorbs less water.
For the person asking about replacing a lifter for the Envoy, keep in mind that most lifters are designed for spas up to 96" x 96" and your spa is larger than that in one direction. If you split the 100" with the fold, you can pretty much use any of the non-gas-shock lifters with the caveat that the bar will not go all the way to the hinge. As you fold the cover over the bar it will slide down an inch or so. Not a big deal especially if you also go with the Cover Saver. You will not be able to use the Cover Valet or Covermate 3 gas-shock lifts because they need to be able to reach the hinge by design. If you split the 91" with the fold, you will need to order either the Covermate 1 or 3 with the long coupler bar or the Cover Genie or Cover Valet since these are basically two independent arms. In either case, a tray type system like the Cover Caddy will work for you. Hope that helps.
