Well, our 9-year-old Hayward pump finally bit the dust a week ago. We have already replaced the motor once. This time we are looking to replace it with a newer model. Our previous model was SP2610X15. I realize they don't make single-speed pumps in 1.5hp any longer. What size should the variable speed replacement be considering our pool has around 15,500 gallons? Would 1.25hp suffice or should it be at least 1.5hp? Trying not to get a pump with more hp than we actually need...