I'm still fairly new to this forum and to pool ownership. I recently bought a house with a pool and spa. They are pretty small as you can see from my signature. Spa is 12 x 4.5 x 3 deep. Pool is 13 x 4.5 x 4 deep. I am looking to buy a new heat pump since the existing one does not work. The big question is sizing. I've received a quote for a 65,000 BTU heat pump and 95,000 BTU heat pump. However, I really don't know how to size them both for getting up to the proper heat and maintaining it. I will be using a solar blanket since it shouldn't be tough work with on small pools. I don't mind paying a little more for a well powered heat pump, but I also don't want to waste money (the whole reason I've chosen a heat pump over a gas heater). I also plan to use the spa on a regular basis during the winter. The pool will be used somewhat in the winter but doesn't need to be as hot. The pool and spa run on the same pump but the lines are isolated. I simply want to be able heat my pools efficiently in a reasonable amount of time. Any thoughts on this or resources for sizing my heat pump?