Quote Originally Posted by digizure View Post
I was just researching and here's what I came up with (by no means I am an electrician).

I have a home made adult rack with two 39ft heat cables, both 100 watts each, plugged into a Herpstat 2. If I were to replace the heat cable with an 11" flexwatt, I'd need 25 feet and they're 20 watts per foot so that's 500 watts and I'd probably hook it up to a Herpstat 1.

Is it safe to assume that the heat cable will save on the electricity bill?
Nope because you don't pay for kilowatts you pay for kilowatt-hours, so your bill depends on how efficiently the tape versus cable transfers heat to the tub, and how long each has to run to maintain the temperature in the tub.