Watermom had been telling me for years that my 1.5 HP pump was likely oversized for my 12,500 pool and 19" sand filter. But the pump was what we had so we waited for it to die, which it did in its 6th season. Not a bad run.

The new one is a 1 HP 2-speed, another Pentair Dynamo. I had occasion to vacuum the pool before closing this past weekend and was truly amazed at how much better it performed. The vacuum suction was much more effective and acted on a greater distance, meaning I could see it suck dirt from farther away. Cleaning the pool took just half the time.

I have no idea why that is but I do now know that bigger is not always better.