With all do respect to Chas, I would just get the 230 hook up to begin with. In my opinion if you’re buying a hot tub it’s probably not with the baby’s food money so why not bite the bullet and do it right the first time. I live in New England and on a cold night your body gets used to the water temperature after a half hour or so. A few degrees drop (say with the jets-on-no-heater-using-110) becomes surprisingly obvious.