We're adding a heater to our pool and trying to decide whether to go with a heat pump or a solar heating system. We're in Arizona, so you'd think that solar heating would be the automatic choice, but I haven't heard anything good from any of the companies I requested estimates from. The company that put in our pool wouldn't even talk about solar units, and they've been in the business for 25 years. They also said they use just one heat pump unit and that was it, a "one size fits all" sort of response. Any advice from you learned souls would be much appreciated.