The industry-regulated max temp provided by inflatable hot tubs is 104 degrees Fahrenheit and most models on the market offer max temps between 100 and 104. While lowering the temperature to 90 degrees between uses might seem like a good idea for the sake of saving energy, it’s worth bearing in mind that the power required to reheat the tub to the recommended temp of 102 degrees will likely undo any saving made by reducing temps when not in use.