Quote Originally Posted by CntrlF8
Don't you think I'd do that if I had the space? I mean, really..
Dude you don't have to get testy, he is only trying to help, relax.

Aside from flexwatt there is also heat rope/cord which Animal plastic and Vision Racks use which could be placed around front side of tubs with a small hole drilled in every shelf to run down to next level and then controled by a thermostat. It is very easy to use and comes in different legnths. Since you can't control the room they are in, which is the ideal way, you may be able to run the heat cord faily easily.

Just a thought.

Insulating isn't your problem. Flexx watt is designed to heat the surface it is in contact with, not the whole tub. I think you will be better off with some kind of secondary heating source controled by a t-stat.