Is extra insulation for an exterior hot tub in a northern region beneficial?

[MarathonMan]

I have a question to pose for those of you that have more knowledge than I do about this. I am considering to add some insulation to the case of my hot tub in effort to lessen the effects of living in a northern region. This is the first winter that my wife and I will have a hot tub. I'm a little concerned how much additional energy it will require to keep said hot tub at temperature. I wasn't going to consider just spraying additional foam but using the spray type foam and using a cardboard box lined with plastic bag and making "bricks" that could be added to the interior without obstructing any piping or pumps. Your thoughts please.

 

[Brian VT]

How about just stuffing lots of bubble wrap in there?
That's what I did where I had to dig out some foam to repair a leak.

 

[kris77]

My neighbor has a older hot tub. I'm in the same region as you. He took the skirt off his hot tub and stuffed in fiberglass insulation. Then used spray adhesive and glued the shiny foil back bubble wrap insulation to the panels. He swears his tub doesnt run as much now.

I'm getting ready to rebuild an old tub and i think i'm going to do the same thing to mine. What's it going to cost??? Maybe $100-$150 for insulation? Thats not a lot to pay if it actually helps. It will pay for itself over time.

EDIT:
Something like this video....
Dennys hot tub restoration - YouTube

 

[Brian VT]

I would be concerned that if the fiberglass insulation got wet then it becomes ineffective and a nasty mess to clean out.

 

[Soupy]

Rock wool is a good alternative to fiberglass, as it doesn't soak up water or lose efffectiveness around water.