We bought this for our 15 foot x 54 in tall round pool. It took some trial and error to get it functional. There wasn't a lot of info online and at one point I thought we bought the wrong wattage and should have bought the 11 kW heater, which meant our $1500 electrical work to wire out to the pool would have been for nothing. But after a lot of research about water math and pump configuration, I learned that this heater is effective once your pool water is above 68F. We opened our pool once the daytime temps started hitting 20C. You also need to control the flow rate for efficient heating so a bypass kit is needed. You'll also need a good solar cover. Over the course of three days in early May, we went from 68F to 85F using a flow rate of 20 and keeping the pool covered. Since May 18, we've kept the heater at 85F and it comes on at night but stays off during the day. When it's been really hot, I turn the heater off. Don't buy more than you need when it comes to an electric heater. Our hydro has increased by $27/month with the heater running. We now enjoy our pool a lot more!

Product was great and the client really likes the digital display.

heats my 12ft pool perfectly