bolds18b

Hi, three questions I'd love some help with. Thanks for reading! 1) Roughly speaking, how many degrees per hour should a 2007 Sundance Marin (320 gallons) warm up if the cover is off (starting from, say, 99 degrees on a 45 degree evening)? 2) What about if the cover is on? 3) Finally, does anyone know if this particular hot tub will still heat while the jets are going, or if it's only one or the other (heater or jets)? I'd have a 220 line. Thanks so much!