Spas will range in the area of $8 - $12 a month to operate. This depends largely on the brand of spa, the size, the frequency of use, the weather and cost of electricity in your area. The difference between "fully foam-filled" and "fully insulated spas" will also have an impact (see below). The largest HotSpring or Caldera spas will run for under $20 per month, guaranteed.

It depends largely on the brand and model of spa. The major difference is that with a 110V system, the heater and the jets will NOT run at the same time. If your spa is well insulated and uses "warm air induction," you will not notice a loss of water warmth during normal usage of a 110V spa.

You buy energy by the KW (killowatt) which heats water at a specific rate regardless of 110V or 220V. A 220V system will heat faster but will NOT be more efficient! To learn more, see 110V vs 220V above. Also, installation of 110V will usually be less expensive than running 220V to your spa.

A spa could have as little as 1/6 inch of insulation on the entire shell and be considered "fully insulated." A fully foam-filled spa is filled from the siding to the inside shell with foam insulation, though the R rating (insulation factor) and type (closed- vs. open-cell) of foam is also important. All HotSpring and Caldera spas are fully foam-filled with closed-cell foam. This protects your hot water with insulation comparable to a commercial freezer. Keeping your hot water hot, instead of allowing it to cool and reheat repeatedly, will keep your energy costs down.