What the sales people know is that HORSEPOWER sells, and filter INCHES do not. I've never seen any evidence that they care enough about anything else to even learn how negatively excess pump size affects pool operation!

It's the same mentality that produced ads associating Marlboro cigarettes with sexy independent toughness, rather than with black and leathery lungs that are prone to cancer, long after EVERYONE knew that that the 2nd association was the true one.