I got to swim yesterday with my 2 beautiful nieces and my brother. The pool was 87°! They heat pump and solar cover are worth every single penny and it truly only took one good day of 80° temps to raise it quickly. The second day of 80° temps took care of the bottom of the pool. I freaking love that heater!!! Temps are supposed to dip into the 50s this week but I'm going to keep it going to see how it does. If I see it struggle I'll shut it down but I dont think it should considering I'm keeping it covered at night. I do pull the cover daily to burn off excessive CCs.